Multimedia information communication system

ABSTRACT

A multimedia information system comprises first and second communication terminal apparatuses for exchanging information data using a common first communication protocol or first and second communication protocols which are different from each other, a first communication network for transmitting information data in accordance with a third communication protocol different from the first and second communication protocols, and first and second communication interface apparatuses for respectively connecting the first and second communication terminal apparatuses to the first communication network, the first communication interface apparatus comprises first conversion means for converting information data in accordance with the first and third communication protocols between the first communication terminal apparatus and the first communication network, and the second communication interface apparatus comprises second conversion means for converting information data in accordance with the second and third communication protocols between the second communication terminal apparatus and the first communication network.

TECHNICAL FIELD

The present invention relates to a multimedia information communicationsystem for serving various kinds of media terminals to have, e.g., a LAN(Local Area Network) as a core.

BACKGROUND ART

As conventional private network systems, a system in which a PBX(Private Branch Exchange) serves voice communication terminals such astelephones and the like as extension terminals, and exchange-connectsbetween these extension terminals and an external communication networksuch as a public network, and between the extension terminals so as toallow conversations, and a system in which data terminals such aspersonal computers and the like are connected to a LAN (Local AreaNetwork), and e-mails and data are transported between the personalcomputers via the LAN are known. A system that links a voicecommunication system using a PBX and a data communication system using aLAN via a gateway has been proposed.

However, in such conventional private network system, independentcommunication infrastructures must be built in correspondence with thevoice communication system and data communication system. The voicecommunication system readily goes system down since it is integrallycontrolled by the PBX. To avoid such problem, the PBXs must beduplicated. For this reason, problems of a large-scale systemarrangement and heavy investment load on the user have been posed.Furthermore, connection of a new terminal, changes in connection, andthe like require setups by maintenance persons, and since the voicecommunication system using the PBX and the data communication systemusing the LAN require different maintenance/management forms,maintenance/management processes are complicated and require high cost.

In order to link the voice communication system and data communicationsystem, the gateway must be placed. Hence, the system arrangementrequires still larger scale and higher cost.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide a low-cost,high-reliability multimedia information communication system which canimplement various kinds of communications by a common communicationinfrastructure without requiring any large-scale equipment such as aPBX, gateway, and the like, and can make an arrangement simple andmaintenance/management easy.

A first multimedia information communication system according to thepresent invention comprises first and second communication terminalapparatuses for exchanging information data using a common firstcommunication protocol or first and second communication protocols whichare different from each other, a first communication network fortransmitting information data in accordance with a third communicationprotocol different from the first and second communication protocols,and first and second communication interface apparatuses forrespectively connecting the first and second communication terminalapparatuses to the first communication network, the first communicationinterface apparatus comprises first conversion means for convertinginformation data in accordance with the first and third communicationprotocols between the first communication terminal apparatus and thefirst communication network, and the second communication interfaceapparatus comprises second conversion means for converting informationdata in accordance with the second and third communication protocolsbetween the second communication terminal apparatus and the firstcommunication network.

Preferred manners of the first multimedia information communicationsystem according to the present invention are as follows.

(1) The system further comprises a third communication interfaceapparatus for connecting the first communication network to a secondcommunication network which transmits information data in accordancewith a fourth communication protocol which is different from at leastthe third communication protocol, and the third communication interfaceapparatus comprises third conversion means for converting informationdata in correspondence with a difference between the third and fourthcommunication protocols between the second and first communicationnetworks.

(2) In the system of (1), at least one of the first, second, and thirdconversion means comprises a plurality of data conversion means providedin correspondence with types of information data, data typedetermination means for determining a type of input information data,and selection means for selectively enabling the plurality of dataconversion means in accordance with a determination result of the datatype determination means to convert the information data.

A second multimedia information communication system according to thepresent invention comprises first and second communication terminalapparatuses for exchanging information data using a common firstcommunication protocol or first and second communication protocols whichare different from each other, a first communication network fortransmitting information data in accordance with a third communicationprotocol different from the first and second communication protocols,first and second communication interface apparatuses for respectivelyconnecting the first and second communication terminal apparatuses tothe first communication network, and a third communication interfaceapparatus for connecting the first communication network to a secondcommunication network for transmitting information data in accordancewith a fourth communication protocol different from the thirdcommunication protocol, and each of the first and second interfaceapparatuses comprises inquiry means for, when a communication terminalapparatus served by the own apparatus generates a call originatingrequest addressed to a communication terminal apparatus served byanother communication interface apparatus, multi-address transmitting aninquiry signal containing first identification information assigned tothe terminating communication terminal apparatus to all communicationinterface apparatuses connected to the first communication network,determination means for, when an inquiry signal reaches via the firstcommunication network, determining if a communication terminal apparatuscorresponding to the first identification information contained in theinquiry signal is served by the own apparatus, response signaltransmission means for, when the determination means determines that thecommunication terminal apparatus of interest is served by the ownapparatus, sending back a response signal containing secondidentification information assigned to the own apparatus on the firstcommunication network to an originating communication interfaceapparatus via the first communication network, and first communicationlink formation means for, when the response signal is sent back,performing processing for forming a communication link between the ownapparatus and the terminating communication interface apparatus on thefirst communication network on the basis of the second identificationinformation contained in the response signal.

Preferred manners of the second multimedia information communicationsystem according to the present invention are as follows.

(1) Each of the first and second communication interface apparatusescomprises identification information storage means for, when theresponse signal is sent back, storing the second identificationinformation contained in the response signal together with firstidentification information corresponding to a partner communicationterminal apparatus in correspondence with each other, first acquisitionmeans for, when a communication terminal apparatus served by the ownapparatus generates a call originating request addressed to acommunication terminal apparatus served by another communicationinterface apparatus, acquiring second identification informationassigned to a communication interface apparatus that serves theterminating communication terminal apparatus from the identificationinformation storage means, and second communication link formation meansfor, when the first acquisition means acquires the second identificationinformation assigned to the terminating communication interfaceapparatus, performing processing for forming a communication link thatconnects between the own communication interface apparatus andterminating communication interface apparatus on the first communicationnetwork on the basis of the second identification information.

(2) In the system of (1), the identification information storage meansstores first identification information and second identificationinformation acquired by the own communication interface apparatus by theinquiry, and first identification information and second identificationinformation acquired by another communication interface apparatus by theinquiry.

(3) The system further comprises a server apparatus, which is connectedto the first communication network, and has a function of intensivelystoring the first identification information and second identificationinformation acquired by the first and second communication interfaceapparatuses by the inquiry, and each of the first and secondcommunication interface apparatuses comprises second acquisition meansfor, when a communication terminal apparatus served by the own apparatusgenerates a call originating request addressed to a communicationterminal apparatus served by another communication interface apparatus,acquiring second identification information assigned to a communicationinterface apparatus that serves the terminating communication terminalapparatus from the server apparatus, and third communication linkformation means for, when the second acquisition means acquires thesecond identification information assigned to the terminatingcommunication interface apparatus, performing processing for forming acommunication link that connects between the own communication interfaceapparatus and terminating communication interface apparatus on the firstcommunication network on the basis of the second identificationinformation.

(4) The third communication interface apparatus comprises identificationinformation storage means for intensively storing the firstidentification information and second identification informationacquired by the first and second communication interface apparatuses bythe inquiry, and each of the first and second communication interfaceapparatuses comprises third acquisition means for, when a communicationterminal apparatus served by the own apparatus generates a calloriginating request addressed to a communication terminal apparatusserved by another communication interface apparatus, acquiring secondidentification information assigned to a communication interfaceapparatus that serves the terminating communication terminal apparatusfrom the identification information storage means of the thirdcommunication interface apparatus, and fourth communication linkformation means for, when the third acquisition means acquires thesecond identification information assigned to the terminatingcommunication interface apparatus, performing processing for forming acommunication link that connects between the own communication interfaceapparatus and terminating communication interface apparatus on the firstcommunication network on the basis of the second identificationinformation.

(5) The system further comprises a server apparatus, which is connectedto the first communication network, and has a function of intensivelystoring the first identification information and second identificationinformation acquired by the first and second communication interfaceapparatuses by the inquiry, and each of the first and secondcommunication interface apparatuses comprises identification informationstorage means for, when a response signal to the inquiry signal is sentback, storing second identification information contained in theresponse signal together with first identification information assignedto a terminating communication terminal apparatus in correspondence witheach other, first search means for, when a communication terminalapparatus served by the own apparatus generates a call originatingrequest addressed to a communication terminal apparatus served byanother communication interface apparatus, searching the identificationinformation storage means of the own apparatus for second identificationinformation assigned to a communication interface apparatus that servesthe terminating communication terminal apparatus, second search meansfor, when the first search means cannot find the second identificationinformation by the search, searching the server apparatus for the secondidentification information, third search means for, when the secondsearch means cannot find the second identification information by thesearch, multi-address transmitting an inquiry signal containing firstidentification information corresponding to the terminatingcommunication terminal apparatus to all communication interfaceapparatuses connected to the first communication network, and acquiringsecond identification information assigned to the communicationinterface apparatus that serves the terminating communication terminalapparatus, on the basis of a response signal to the inquiry signal, andfifth communication link formation means for, when one of the first,second, and third search means acquires the second identificationinformation assigned to the communication interface apparatus thatserves the terminating communication terminal apparatus, performingprocessing for forming a communication link for connecting between theown communication interface apparatus and terminating communicationinterface apparatus on the first communication network on the basis ofthe second identification information.

A third multimedia information communication system according to thepresent invention comprises first and second communication terminalapparatuses for exchanging information data using a common firstcommunication protocol or first and second communication protocols whichare different from each other, a first communication network fortransmitting information data in accordance with a third communicationprotocol different from the first and second communication protocols,first and second communication interface apparatuses for respectivelyconnecting the first and second communication terminal apparatuses tothe first communication network, and a third communication interfaceapparatus for connecting the first communication network to a secondcommunication network for transmitting information data in accordancewith a fourth communication protocol different from the thirdcommunication protocol, each of the first and second interfaceapparatuses comprises inquiry signal transmission means for, when acommunication terminal apparatus served by the own apparatus generates acall originating request addressed to a communication terminal apparatusserved by another communication interface apparatus, transmitting aninquiry signal containing identification information corresponding tothe terminating communication terminal apparatus onto the firstcommunication network, and the third communication interface apparatuscomprises terminating apparatus determination means for receiving theinquiry signal, and determining based on the identification informationcontained in the inquiry signal if the terminating communicationterminal apparatus is a communication terminal apparatus which is servedby the first or second communication interface apparatus inside thesystem, or a communication terminal apparatus which is connected to thesecond communication network outside the system, and communication linkformation means for selectively performing first processing for forminga communication link for connecting between the first or secondcommunication interface apparatus that serves an originatingcommunication terminal apparatus and the first or second communicationinterface apparatus that serves the terminating communication terminalapparatus, and second control for forming a communication link betweenthe first or second communication interface apparatus that serves theoriginating communication terminal apparatus and the terminatingcommunication terminal apparatus connected to the second communicationnetwork, in accordance with a determination result of the terminatingapparatus determination means.

The third multimedia information communication system according to thepresent invention may further comprise a server apparatus, and theserver apparatus may comprise terminating apparatus determination meansand communication link forming means equipped in the third communicationinterface apparatus.

Preferred manners of the third multimedia information communicationsystem according to the present invention are as follows.

(1) The communication link formation means performs, as the firstcontrol, control for sending back a response signal containing secondidentification information assigned to a communication interfaceapparatus that serves the terminating communication terminal apparatusto the communication interface apparatus as an inquiry source, andforming a communication link that connects between a communicationinterface apparatus that serves an originating communication terminalapparatus, and the communication interface apparatus that serves theterminating communication terminal apparatus, and as the second control,processing for sending back a response signal containing secondidentification information assigned to the third communication interfaceapparatus to the communication interface apparatus as an inquiry source,forming an internal communication link that connects the originatingcommunication interface apparatus and the third communication interfaceapparatus on the first communication network, forming an externalcommunication link between the terminating external communicationterminal apparatus and the third communication interface apparatus byrequesting a call connection to the second communication network, andconnecting the internal and external communication links to each other.

(2) The terminating apparatus determination means comprisesidentification information storage means for prestoring firstidentification information assigned to the first and secondcommunication interface apparatuses, and first identificationinformation of each communication terminal apparatuses served by thecommunication interface apparatuses in correspondence with each other,and determines if the terminating communication terminal apparatus is acommunication terminal apparatus inside or outside the system bychecking if first identification information of a terminating apparatuscontained in the received inquiry signal is stored in the identificationinformation storage means.

(3) In the system of (2), the terminating apparatus determination meanscomprises identification information storage means for prestoring firstidentification information assigned to the first and secondcommunication interface apparatuses, and first identificationinformation of each communication terminal apparatuses served by thecommunication interface apparatuses in correspondence with each other,and determines if the terminating communication terminal apparatus is acommunication terminal apparatus inside or outside the system bychecking if first identification information of a terminating apparatuscontained in the received inquiry signal is stored in the identificationinformation storage means.

(4) When a received inquiry signal contains information indicatingwhether or not a call is originated to the second communication network,the terminating apparatus determination means determines based on theinformation if the terminating communication terminal apparatus is acommunication terminal apparatus inside or outside the system.

A fourth multimedia information communication system according to thepresent invention comprises first and second communication terminalapparatuses for exchanging information data using a common firstcommunication protocol or first and second communication protocols whichare different from each other, a first communication network fortransmitting information data in accordance with a third communicationprotocol different from the first and second communication protocols,first and second communication interface apparatuses for respectivelyconnecting the first and second communication terminal apparatuses tothe first communication network, and a third communication interfaceapparatus for connecting the first communication network to a secondcommunication network for transmitting information data in accordancewith a fourth communication protocol different from the thirdcommunication protocol, and each of the first and second communicationinterface apparatuses comprises terminating apparatus determinationmeans for, when a communication terminal apparatus served by the ownapparatus generates a call originating request addressed to anothercommunication terminal apparatus, determining if the terminatingcommunication terminal apparatus is a communication terminal apparatuswhich is served by the first or second interface apparatus inside thesystem, or a communication terminal apparatus which is connected to thesecond communication network outside the system, and communication linkformation means for selectively performing first control for forming acommunication link for connecting between the own communicationinterface apparatus and a communication interface apparatus that servesthe terminating communication terminal apparatus, and second control forforming a communication link for connecting between the owncommunication interface apparatus and the terminating communicationterminal apparatus connected to the second communication network, inaccordance with a determination result of the terminating apparatusdetermination means.

Preferred manners of the fourth multimedia information communicationsystem according to the present invention are as follows.

(1) The terminating apparatus determination means comprises inquirymeans for, when a communication terminal apparatus served by the owncommunication interface apparatus generates a call originating requestaddressed to another communication terminal apparatus, multi-addresstransmitting an inquiry signal containing identification informationcorresponding to the terminating communication terminal apparatus to allcommunication interface apparatuses connected to the first communicationnetwork, and determination means for determining if the terminatingother communication terminal apparatus is a communication terminalapparatus inside or outside the system by monitoring whether or not oneof the communication interface apparatuses connected to the firstcommunication network sends back a response signal indicating that theapparatus serves the terminating other communication terminal apparatus,after the inquiry signal is transmitted.

(2) In the system of (1), the terminating apparatus determination meanscomprises identification information storage means for, when theresponse signal is sent back, storing second identification information,which is contained in the response signal, and corresponds to acommunication interface apparatus that sent back the response signal,together with first identification information corresponding to theterminating communication terminal apparatus in correspondence with eachother, and determination means for, when a communication terminalapparatus served by the own communication interface apparatus generatesa call originating request addressed to another communication terminalapparatus, searching the identification information storage means forsecond identification information assigned to a communication interfaceapparatus that serves the terminating communication terminal apparatus,and determining based on the presence/absence of the secondidentification information if the terminating communication terminalapparatus is a communication terminal apparatus inside or outside thesystem.

(3) When a call originating request sent from an originatingcommunication terminal apparatus contains information indicating whetheror not a call is originated to the second communication network, theterminating apparatus determination means determines based on thisinformation if the terminating communication terminal apparatus is acommunication terminal apparatus inside or outside the system.

A fifth multimedia information communication system according to thepresent invention comprises first and second communication terminalapparatuses for exchanging information data using a common firstcommunication protocol or first and second communication protocols whichare different from each other, a first communication network fortransmitting information data in accordance with a third communicationprotocol different from the first and second communication protocols,first and second communication interface apparatuses for respectivelyconnecting the first and second communication terminal apparatuses tothe first communication network, and a third communication interfaceapparatus for connecting the first communication network to a secondcommunication network for transmitting information data in accordancewith a fourth communication protocol different from the thirdcommunication protocol, and the third communication interface apparatuscomprises first identification information acquisition means for, whenan incoming call signal reaches from an external communication terminalapparatus via the second communication network, acquiring firstidentification information corresponding to a terminating communicationterminal apparatus served by the first or second communication interfaceapparatus on the basis of information representing a terminatingapparatus contained in the incoming call signal, second identificationinformation acquisition means for acquiring second identificationinformation assigned to the first or second communication interfaceapparatus that serves the terminating communication terminal apparatuson the basis of the first identification information acquired by thefirst identification information acquisition means, and communicationlink formation means for forming a communication link that connectsbetween the third communication interface apparatus and the first orsecond communication interface apparatus that serves the terminatingcommunication terminal apparatus on the first communication network onthe basis of the second identification information acquired by thesecond identification information acquisition means.

Preferred manners of the fifth multimedia information communicationsystem according to the present invention are as follows.

(1) When the incoming call signal coming from the external communicationterminal apparatus contains at least one of identification informationcorresponding to a terminating communication terminal apparatus and acommunication type, the first identification information acquisitionmeans determines a terminating communication terminal apparatus on thebasis of at least one of the identification information andcommunication type, and acquires first identification informationassigned to the determined communication terminal apparatus.

(2) When the incoming call signal coming from the external communicationterminal apparatus contains identification information of an originatingcommunication terminal apparatus, the first identification informationacquisition means determines a terminating communication terminalapparatus on the basis of the identification information, and acquiresfirst identification information assigned to the determinedcommunication terminal apparatus.

Preferred manners of the first to fifth multimedia informationcommunication systems according to the present invention are as follows.

(1) Each of the first and second communication interface apparatusescomprises communication interface means for communicating with the firstcommunication network, codec means for decoding information obtainedfrom the first communication network by the communication interfacemeans or encoding information to be output to the first communicationnetwork, a PB receiver for decoding a PB signal from the first andsecond communication terminal apparatuses, and tone generation means forgenerating a call progress tone for the first and second communicationterminal apparatuses.

(2) In the system of (1), each of the first and second communicationinterface apparatuses further comprises means for connecting a pluralityof communication interface means equivalent to the communicationinterface means to the first communication network.

(3) Each of the first and second communication interface apparatusescomprises communication interface means for communicating with the firstcommunication network, codec means for decoding information obtainedfrom the first communication network by the communication interfacemeans or encoding information to be output to the first communicationnetwork, a PB receiver for decoding a PB signal from the first andsecond communication terminal apparatuses, and radio means for making aninformation communication with a radio station.

(4) The third communication interface apparatus comprises firstcommunication interface means for communicating with the firstcommunication network, codec means for decoding information obtainedfrom the first communication network or information obtained from thesecond communication network by the communication interface means, orencoding information to be output to the first or second communicationnetwork, a PB receiver for decoding a PB signal from the secondcommunication network, and second communication interface means forcommunicating with the second communication network.

(5) The third communication interface apparatus comprises firstcommunication interface means for communicating with the firstcommunication network, codec means for decoding information obtainedfrom the first communication network by the communication interfacemeans, or encoding information to be output to the first communicationnetwork, and second communication interface means for communicating withthe second communication network.

A sixth multimedia information communication system according to thepresent invention comprises a plurality of interface apparatuses, eachof which is connected to a communication terminal, and has protocolconversion means for converting a first communication protocol unique tothe communication terminal into a second communication protocoldifferent from the first communication protocol, and vice versa, anetwork for connecting the interface apparatuses to each other andtransmitting a signal in accordance with the second communicationprotocol, and a communication connection controller for controlling acommunication between the plurality of terminal devices, and thecommunication connection controller is provided to at least one of theinterface apparatuses.

Preferred manners of the sixth multimedia information communicationsystem according to the present invention are as follows.

(1) The system further comprises a computer which is connected to thenetwork and has a telephone function, and the communication connectioncontroller is provided to the at least one interface apparatus and thecomputer.

(2) The system further comprises a server which is connected to thenetwork and has the communication connection controller.

(3) Each of the interface apparatuses transmits, to one communicationconnection controller, originating side information that pertains to theinterface apparatus which is to initiate a communication, terminatingside information that pertains to the interface apparatus which is tocommunicate with, and communication condition information that pertainsto communication means for performing a communication, at the beginningof the communication.

(4) In the system of (3), the communication controller acquires detailedoriginating side information, terminating side information, andcommunication condition information from a database on the network orthe interface apparatus on the basis of the received originating sideinformation, terminating side information, and communication conditioninformation, selects an appropriate communication connection controlleron the basis of the acquired information and information that pertainsto a status of the network at the time of the communication, andtransmits information that pertains to the selected communicationconnection controller to originating and terminating side interfaceapparatuses.

(5) In the system of (4), each of the interface apparatuses furthercomprises means for monitoring a communication state from theoriginating side interface apparatus to the terminating side interfaceapparatus.

(6) In the system of (3), the originating side information contains atelephone number, network number, and login name, and the communicationcondition information contains an audio communication, imagecommunication, and data communication.

(7) In the system of (3), the terminating side information contains atelephone number, network number, login name, and group informationrequired for a communication.

(8) The communication connection controller further comprises means forchanging a terminating side interface apparatus in correspondence with arequest from an originating or terminating side interface apparatus or achange in status of the network even after the beginning of thecommunication between the interface apparatuses.

(9) The system further comprises means for changing the communicationconnection controller in correspondence with a request from anoriginating or terminating side interface apparatus or a change instatus of the network even after the beginning of the communicationbetween the interface apparatuses.

(10) The system further comprises means for changing a communicationconnection mode in correspondence with a request from an originating orterminating side interface apparatus or a change in status of thenetwork even after the beginning of the communication between theinterface apparatuses.

(11) A third interface apparatus different from originating andterminating side interface apparatuses sends information of theoriginating and terminating side interface apparatuses to onecommunication connection controller to call the originating andterminating side interface apparatuses in turn and to connect theoriginating and terminating side interface apparatuses to each other soas to make the originating and terminating side interface apparatusescommunicate with each other.

(12) When a terminating side interface apparatus cannot answer a call, athird interface apparatus answers as proxy for the terminating sideinterface apparatus, stores communicating information, and transfers thestored information upon call termination to the terminating sideinterface apparatus.

(13) The system further comprises means for converting e-mail text intoaudio data, and wherein audio data of an e-mail addressed to anoriginating side interface apparatus is transmitted to the originatingside interface apparatus in response to a request from the originatingside interface apparatus.

(14) The network transmits a signal in accordance with a protocolcomplying with an IEEE802 interface.

(15) The network transmits a signal in accordance with a protocolcomplying with an IEEE1394 interface.

According to the present invention, for example, both an audio signaltransmitted from a voice communication terminal and data transmittedfrom a data terminal such as a personal computer are converted into anidentical data format corresponding to a communication protocol of afirst communication network by a communication interface apparatus, andthe converted data are then sent onto the first communication network.The data transferred on the first communication network is convertedinto a data format corresponding to a communication protocol of a voicecommunication terminal or data terminal by a terminating communicationinterface apparatus, and is then sent to a terminal apparatus. For thisreason, a plurality of kinds of communications can be implemented usinga single infrastructure, i.e., the first communication network.

In addition, the data conversion processes of the respective terminalapparatuses are distributed to communication interface apparatusescorresponding to the terminal apparatuses, and each communicationinterface apparatus need only have a data conversion function between,e.g., one type of communication protocol on the terminal apparatus sideand only one type of communication protocol on the first communicationnetwork side, and need not have all data conversion functionscorresponding to a plurality of types of communication protocols versusa plurality of types of communication protocols. For this reason, nolarge-scale communication equipment for integrated processing such asduplicated PBXs, gateway, and the like is required, and a system can berealized by preparing a plurality of communication interface apparatuseshaving simple functions, thus attaining a simple system arrangement anda great cost reduction.

Upon connecting a new terminal apparatus or changing connections, afteran arbitrary terminal apparatus is connected to the first communicationnetwork via a communication interface apparatus, a simple setup processneed only be done without requiring any complicated setups. Hence, asystem which has high expandability and allows easy maintenance-management can be provided.

As described above, according to the present invention, a low-cost,high-reliability multimedia information communication system which canimplement a plurality of kinds of communications by a commoncommunication infrastructure without equipping any large-scale equipmentsuch as a PBX, gateway, and the like, and can make an arrangement simpleand maintenance/management easy can be provided.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic block diagram showing an embodiment of amultimedia information communication system according to the presentinvention;

FIG. 2 is a block diagram showing the functional arrangement of a systemwhich can also connect business telephones and personal computers;

FIG. 3 is a block diagram showing the functional arrangement of a radiobase station 2;

FIG. 4 is a block diagram showing the functional arrangement of analogtelephone hub apparatuses 3-1 and 3-2 f;

FIG. 5 is a block diagram showing the functional arrangement of abusiness telephone hub apparatus 4;

FIG. 6 is a block diagram showing the functional arrangement of an ISDNrouter apparatus 5;

FIG. 7 is a block diagram showing the functional arrangement of a PSTNrouter apparatus 6;

FIG. 8 is a sequence chart upon extension-to-extension communicationbetween a radio terminal PS and analog telephone TEL1;

FIG. 9 is a sequence chart showing the first example uponextension-to-extension communication between analog telephones;

FIG. 10 is a sequence chart showing the second example uponextension-to-extension communication between analog telephones;

FIG. 11 is a sequence chart showing the third example uponextension-to-extension communication between analog telephones;

FIG. 12 is an operation sequence chart upon connecting extensionterminals by inquiring of the router apparatus 5 as to an IP address;

FIG. 13 is a sequence chart upon extension-to-extension voicecommunication between an analog telephone and personal computer;

FIG. 14 is a sequence chart upon extension-to-extension voicecommunication between personal computers;

FIG. 15 is a sequence chart upon extension-to-extension datacommunication between personal computers;

FIG. 16 is a sequence chart showing the first example upon voicecommunication between an outside-line data terminal and an extensionanalog telephone;

FIG. 17 is a sequence chart showing the second example upon voicecommunication between an outside-line data terminal and an extensionanalog telephone;

FIG. 18 is a sequence chart upon data communication between anoutside-line data terminal and an extension data terminal;

FIG. 19 is a sequence chart upon voice communication between an analogtelephone and an external telephone;

FIG. 20 is a sequence chart showing an example upon voice communicationbetween an analog telephone and an external telephone;

FIG. 21 is a sequence chart showing another example upon voicecommunication between an extension analog telephone and an externaltelephone;

FIG. 22 is a sequence chart upon voice communication between anextension analog telephone and an outside-line data terminal;

FIG. 23 is a sequence chart upon data communication between an extensiondata terminal and an outside-line data terminal;

FIG. 24 is a diagram showing an example of DN or IP addresses assignedto the respective apparatuses in the system;

FIG. 25 is a sequence chart showing the operation of a router apparatuswhich determines the terminating apparatus on the basis of its owndatabase upon placing a call from an extension terminal onto an outsideline;

FIG. 26 is a table showing an example of the configuration of an IPaddress search database provided to the router apparatus;

FIG. 27 is a sequence chart showing the operation of a router apparatuswhich determines the terminating apparatus on the basis of a specialservice code upon placing a call from an extension terminal to anoutside line;

FIG. 28 is a sequence chart showing the operation of a content serverwhich determines the terminating apparatus on the basis of its owndatabase upon placing a call from an extension terminal to an outsideline;

FIG. 29 is a table showing an example of the configuration of an IPaddress search database provided to the content server;

FIG. 30 is a sequence chart showing the operation of a content serverwhich determines the terminating apparatus on the basis of a specialservice code upon placing a call from an extension terminal to anoutside line;

FIG. 31 is a sequence chart showing the operation of a hub apparatuswhich determines the terminating apparatus on the basis of its owndatabase upon placing a call from an extension terminal to an outsideline;

FIG. 32 is a table showing an example of the configuration of an IPaddress search database provided to the hub apparatus;

FIG. 33 is a sequence chart showing the operation of a hub apparatuswhich determines the terminating apparatus on the basis of a specialservice code upon placing a call from an extension terminal to anoutside line;

FIG. 34 is a sequence chart showing the operation for determining theterminating apparatus on the basis of a received sub-address uponreceiving an incoming call from an outside line;

FIG. 35 is a table showing an example of the configuration of asub-address database provided to a router apparatus;

FIG. 36 is a sequence chart showing the operation for determining theterminating apparatus on the basis of the communication type expressedby a received sub-address upon receiving an incoming call from anoutside line;

FIG. 37 is a table showing an example of the configuration of acommunication type database provided to a router apparatus;

FIG. 38 is a sequence chart showing the operation for determining theterminating apparatus on the basis of the DN of the originatingapparatus upon receiving an incoming call from an outside line;

FIG. 39 is a table showing an example of the configuration of a callerdatabase provided to a router apparatus;

FIG. 40 is a block diagram showing an embodiment of a hub apparatusaccording to the present invention;

FIG. 41 is a block diagram showing the first modification of the hubapparatus shown in FIG. 40;

FIG. 42 is a block diagram showing the second modification of the hubapparatus shown in FIG. 40;

FIG. 43 is a block diagram showing an embodiment of an ISDN routerapparatus according to the present invention;

FIG. 44 is a block diagram showing an embodiment of a public networkrouter apparatus according to the present invention;

FIG. 45 is a block diagram showing an embodiment of a radio hubapparatus according to the present invention;

FIG. 46 is a schematic diagram showing the second embodiment of amultimedia information communication system according to the presentinvention;

FIG. 47 is a block diagram showing the arrangement of an interfaceapparatus shown in FIG. 46 in detail;

FIG. 48 is a chart showing the communication sequence of the secondembodiment;

FIG. 49 is a diagram showing an arrangement for implementing a voicemail in the second embodiment; and

FIG. 50 is a diagram showing an arrangement for implementing a mailtext-to-speech function in the second embodiment.

BEST MODE OF CARRYING OUT THE INVENTION

FIG. 1 is a schematic diagram showing an embodiment of a multimediainformation communication system according to the present invention.Referring to FIG. 1, a LAN 1 serves as a core of this system, and iscomprised of Ethernet having a transmission capacity of, e.g., 100 Mbitsor 1 Gbits.

A radio base station 2 and a plurality of analog telephone hubapparatuses 3-1 and 3-2 are connected to this LAN 1 as communicationinterface apparatuses for extension connections. The radio base station2 has a function of a base station for, e.g., a PHS (Personal HandyphoneSystem), and a radio terminal PS is connected to this radio base station2 via a radio channel. A plurality of analog telephones TEL1 to TEL5 areconnected to the analog telephone hub apparatuses 3-1 and 3-2. The radioterminal PS and analog telephones TEL1 to TEL5 are used as extensionterminals.

Also, an ISDN router apparatus 5 and PSTN router apparatus 6 areconnected to the LAN 1 as communication interface apparatuses foroutside-line connections. The ISDN router apparatus 5 connects the LAN 1to an ISDN 7. The PSTN router apparatus 6 connects the LAN 1 to a PSTN8.

Furthermore, a communication server 9 is connected to the LAN 1. Thecommunication server 9 comprises a network interface (I/F) 9 d forinterfacing with the LAN 1, a driver 9 c for driving a hard disk device(not shown) and the like, an OS (operating system) 9 b, and anapplication program 9 a. The communication server 9 has a function ofsaving address information of the communication interface apparatuses 2to 6 and the extension terminals connected thereto in a database, andsearching the database and sending back a result obtained by search toan inquiry source when the communication interface apparatuses 2 to 6inquire of the server about addresses.

The LAN 1 can serve business telephones, and data terminal apparatusessuch as personal computers and the like, as extension terminals. FIG. 2is a block diagram showing the functional arrangement of a system thatcan connect these business telephones and personal computers.

Referring to FIG. 2, a business telephone hub apparatus 4 and a hubapparatus 70 for a personal computer are connected to the LAN 1. Aplurality of business telephones DKT1 and DKT2 are connected to thebusiness telephone hub apparatus 4. These business telephones DKT1 andDKT2 comprise digital multi-functional telephones. The hub apparatus 70comprises a network I/F 70 a for interfacing with the LAN 1, and aplurality of personal computers PC1 and PC2 are connected to the networkI/F 70 a. These personal computers PC1 and PC2 have a data communicationfunction.

The radio base station 2, analog telephone hub apparatuses 3-1 and 3-2,and business telephone hub apparatus 4 provided to that above system asextension communication interface apparatuses have the followingarrangements.

FIG. 3 is a block diagram showing the functional arrangement of theradio base station 2. The radio base station 2 comprises a networkinterface (I/F) 2 a for interfacing with the LAN 1, a network protocolprocessor 2 d, a radio unit 2 b for exchanging radio signals with theradio terminal PS, a radio protocol processor 2 e, and a radio/networkprotocol converter 2 c. Of these units, the network protocol processor 2d controls data transmission with the LAN 1 in accordance with a networkprotocol defined with the radio terminal PS. The radio/network protocolconverter 2 c performs protocol conversion between the network protocoland radio protocol.

Also, the radio base station 2 comprises a connection controller 2 f,destination information storage/search unit 2 g, and destinationdatabase 2 h, and further a data type identification/storage unit 2 i,data packet converter 2 k, audio signal converter 2 j, and image signalconverter 2 m. Upon reception of a call request from the radio terminalPS, the connection controller 2 f inquires of other communicationinterface apparatuses connected to the LAN 1 to confirm the location ofthe destination terminal, and executes control for forming acommunication link for connecting the radio terminal PS and thecommunication partner terminal on the LAN 1 on the basis of theconfirmation result. The destination information storage/search unit 2 gstores the LAN address of the communication interface apparatus thatserves the destination communication terminal acquired by the inquiry ofthe connection controller 2 f in the destination database 2 h togetherwith the address of the destination communication terminal. The datatype identification/storage unit 2 i has a function of determining andstoring the type of data received from the LAN 1.

The audio signal converter 2 j converts audio data coming from the radioterminal PS into a format suitable for packetization. The image signalconverter 2 m,converts,image data coming from the radio terminal PS intoa format suitable for packetization. The data packet converter 2 k formspackets by breaking up the audio and image data in units ofpredetermined block lengths.

FIG. 4 is a block diagram showing the functional arrangement of theanalog telephone hub apparatuses 3-1 and 3-2. The difference between thearrangements of the analog telephone hub apparatuses 3-1 and 3-2, andthe radio base station 2 lies in that they comprise an analog telephoneinterface (I/F) 3 b, analog telephone protocol processor 3 e, and analogtelephone/network protocol converter 3 c in place of the radio unit 2 b,radio protocol processor 2 e, and radio/network protocol converter 2 c.

The analog telephone I/F 3 b exchanges audio signal with the analogtelephones TEL1 to TEL5. The analog telephone protocol processor 3 econtrols telephone communications in accordance with a communicationprotocol defined with the analog telephones TEL1 to TEL5. The analogtelephone/network protocol converter 3 c performs protocol conversionbetween the network protocol and analog telephone protocol.

FIG. 5 is a block diagram showing the functional arrangement of thebusiness telephone hub apparatus 4. The difference between thearrangements of this business telephone hub apparatus 4, and the analogtelephone hub apparatuses 3-1 and 3-2 lies in that it comprises abusiness telephone interface (I/F) 4 b, business telephone protocolprocessor 4 e, and business telephone/network protocol converter 4 c inplace of the analog telephone interface (I/F) 3 b, analog telephoneprotocol processor 3 e, and analog telephone/network protocol converter3 c.

The business telephone I/F 4 b exchanges audio data signals with thebusiness telephones DKT1 and DKT2. The business telephone protocolprocessor 4 e controls digital telephone communications in accordancewith a communication protocol defined with the business telephones DKT1and DKT2. The business telephone/network protocol converter 4 c performsprotocol conversion between the network protocol and business telephoneprotocol.

The ISDN router apparatus 5 and PSTN router apparatus 6 provided to thesystem as outside-line communication interface apparatuses have thefollowing arrangements.

FIG. 6 is a block diagram showing the functional arrangement of the ISDNrouter apparatus 5. This ISDN telephone hub apparatus 5 is differentfrom the arrangement of the analog telephone hub apparatuses 3-1 and 3-2in that it comprises an ISDN interface (I/F) 5 b, ISDN protocolprocessor 5e, and ISDN/network protocol converter 5 c.

The ISDN I/F 5 b exchanges data signals with the ISDN. The ISDN protocolprocessor 5 e controls digital telephone communications in accordancewith a communication protocol defined with the ISDN. The ISDN/networkprotocol converter 5 c performs protocol conversion between the networkprotocol and business telephone protocol.

FIG. 7 is a block diagram showing the functional arrangement of the PSTNrouter apparatus 6. The difference between the arrangements of this PSTNrouter apparatus 6 and the ISDN router apparatus 5 lies in that itcomprises a PSTN interface (I/F) 6 b, PSTN protocol processor 6 e, andPSTN/network protocol converter 6 c in place of the ISDN interface (I/F)5 b, ISDN protocol processor 5 e, and ISDN/network protocol converter 5c.

The PSTN I/F 6 b exchanges data signals with the PSTN. The PSTN protocolprocessor 6 e controls digital telephone communications in accordancewith a communication protocol defined with the PSTN. The PSTN/networkprotocol converter 6 c performs protocol conversion between the networkprotocol and ISDN protocol.

Various communication processes of the system with the above-mentionedarrangement will be explained below using sequence charts.

(1) When extension-to-extension communication is made between radioterminal PS and analog telephone TEL1

FIG. 8 shows the sequence. Upon reception of a setup message from theradio terminal PS, the radio base station 2 checks if destinationinformation contained in the setup message indicates the network addressitself. If the destination information does not indicate the networkaddress, the destination information storage/search unit 2 g accessesthe destination database 2 h in accordance with an instruction from theconnection controller 2 f to retrieve a network address corresponding tothe destination address contained in the setup message from thedestination database 2 h. The data type identification/storage unit 2 ichecks if the data type in the setup message indicates audio or data,and stores the result.

The radio/network protocol converter 2 c reassembles a setup messagecomplying with the network protocol on the basis of the received setupmessage and the retrieved destination network address, and transmits thereassembled setup message onto the LAN 1 from the network I/F 2 a towardthe terminating analog telephone hub apparatus 3-1 under the control ofthe network protocol processor 2 d.

Upon receiving the setup message addressed to the own apparatus via theLAN 1, the analog telephone hub apparatus 3-1 identifies the terminatinganalog telephone TEL1 from the received setup message. The analogtelephone/network protocol converter 3 creassembles a setup messagecomplying with the communication protocol for the analog telephone, andtransmits the reassembled setup message from the analog telephone I/F 3b to the terminating analog telephone TEL1 under the control of theanalog telephone protocol processor 3 e. When the user goes off-hook toanswer the received setup message, the analog telephone TEL1 sends backa connect message.

When the analog telephone hub apparatus 3-1 has received the connectmessage sent back from the terminating analog telephone TEL1, the analogtelephone/network protocol converter 3 c reassembles a connect messagecomplying with the network protocol, and outputs this connect messageonto the LAN 1 toward the originating radio base station 2.

When the radio base station 2 has received this connect message via thenetwork I/F 2 a, the data type identification/storage unit 2 iidentifies if the data type in this connect message indicates audio ordata, and stores the result. The radio/network protocol converter 2 creassembles a connect message complying with the radio protocol on thebasis of the received connect message, and outputs the reassembledconnect message from the radio unit 2 b toward the radio terminal PSunder the control of the radio protocol processor 2 e.

In this manner, a communication link via the LAN 1 is formed between theoriginating radio terminal PS and terminating analog telephone TEL1, andthese terminals proceed to make an extension-to-extension call asfollows.

More specifically, upon reception of audio data from the radio terminalPS, the radio base station 2 recognizes with reference to the data typeidentification/storage unit 2 i if the data type is audio. The radiobase station 2 sends the received audio data to the audio signalconverter 2 j on the basis of the recognition result to convert theaudio data, then packetizes the converted data by the data packetconverter 22 k, and transmits that audio packet from the network I/F 2 aonto the LAN 1.

By contrast, upon receiving an audio packet from the analog telephonehub apparatus 3-1 via the LAN 1, the radio base station 2 confirms withreference to the data type identification/storage unit 2 j if thereceived audio packet contains audio data, reconstructs a datastreamfrom the received audio packet using the packet converter 2 k, andconverts the datastream into a signal format suitable for the radioterminal by the audio signal converter 2 j. Then, the audio data istransmitted from the radio unit 2 b toward the radio terminal PS.

Note that the analog telephone hub apparatus 3-1 performs the same audiodata conversion as in the radio base station 2. More specifically, anaudio packet received from the LAN 1 is converted into an analog audiosignal corresponding to the analog telephone TEL1 by a data packetconverter 3 k and audio signal converter 3 j, and the analog audiosignal is then sent from the analog telephone I/F 3 b to the analogtelephone TEl1. On the other hand, an audio signal sent from the analogtelephone TEL1 is converted into a digital signal by the audio signalconverter 3 j, and is packetized by the data packet converter 3 k toform an audio packet. The audio packet is transmitted onto the LAN 1from the network I/F 3 a toward the radio base station 2.

(2) When extension-to-extension communication is made between analogtelephones

FIGS. 9, 10, and 11 show that sequence. A case will be exemplified belowwherein the analog telephone TEL1 assigned dial No. 1000 places a callto the analog telephone TEL4 assigned dial No. 1010.

Assume that the user lifts the handset of the analog telephone TEL1, anddial-inputs dial No. “1010” of the communication partner after he or shehas confirmed a dial tone. In response to this operation, the analogtelephone hub apparatus 3-1 makes dial analysis of a call terminatingapparatus upon receiving all the digits of the dial number from theanalog telephone TEL1, and acquires the IP address of the terminatinghub apparatus. This dial analysis is done by searching a telephonenumber versus hub apparatus IP address conversion table stored in adestination database 3 h. As a result of this search, if the IP addressof the hub apparatus corresponding to the dial number of the terminatingapparatus is successfully acquired, a setup message is generated, and issent onto the LAN 1 toward the terminating hub apparatus.

By contrast, if the IP address of the hub apparatus corresponding to thedial number of the terminating apparatus is not stored in thedestination database 3 h, the analog telephone hub apparatus 3-1inquires of the communication server 9. FIG. 11 shows the inquirysequence. Upon reception of the above-mentioned inquiry message, theserver 9 accesses a conversion table using DN “1010” contained in theinquiry message as a key to search for the IP address of thecorresponding hub apparatus. If the IP address is found, that IP addressis sent to the analog telephone hub apparatus 3-1 as an inquiry sourceusing a response message. Upon reception of this IP address message, theanalog telephone hub apparatus 3-1 generates a setup message, andtransmits it onto the LAN 1 toward the terminating analog telephone hubapparatus 3-2.

On the other hand, assume that no IP address corresponding to thatinquiry is stored in the conversion table of the server 9, and aresponse message indicating this is sent back to the analog telephonehub apparatus 3-1 as an inquiry source. In this case, the analogtelephone hub apparatus 3-1 issues a multi-address request to all thehub apparatuses connected to the LAN 1. FIG. 10 shows the sequence insuch case.

More specifically, the analog telephone hub apparatus 3-1 generates arequest message and sends it onto the LAN 1. Upon reception of therequest message via the LAN 1, all the hub apparatuses connected to theLAN 1 search their destination databases 3 h to check if a communicationterminal corresponding to DN “1010” contained in that request message isserved by the own apparatus. If a given hub apparatus determines that itserves the communication terminal in question, it sends a requestresponse message indicating this to the analog telephone hub apparatus3-1 as a request source. If it is determined that the own apparatus doesnot serve the communication terminal corresponding to requested DN“1010”, no response message is sent back.

If the request response message is sent back from one of the hubapparatuses (e.g., the analog telephone hub apparatus 3-2) in responseto the request, the analog telephone hub apparatus 3-1 transmits a setupmessage toward the terminating analog telephone hub apparatus 3-2 usingas a destination address the IP address contained in that requestresponse message.

If no request response message is sent back from any of the hubapparatuses within a predetermined period of time, the analog telephonehub apparatus 3-1 determines a dial error of the originating analogtelephone, and disconnects a DC loop with the analog telephone TEL1.Note that a message indicating a connection failure such as a messageindicating a dial error or the like may be sent to the originatinganalog telephone and may be visibly or audibly output.

Upon receiving the setup message addressed to the own apparatus, theanalog telephone hub apparatus 3-2 on the terminating side sends back acall setup acceptance (call proc) to the analog telephone hub apparatus3-1 on the originating side, and analyzes the received setup message. Atthis time, in a protocol defined in H323, the setup message contains acall setup, call number “1010”, and transmission performance: datatype=“audio”. The analog telephone hub apparatus 3-2 determines theterminating analog telephone TEL4 and data type from such information.Based on the determination result, a call termination signal is outputto the terminating analog telephone TEL4 to signal reception of anincoming call. At this time, a ringer signal (Alert) is output to theoriginating analog telephone hub apparatus 3-1. Upon receiving theringer signal, the analog telephone hub apparatus 3-1 generates a ringback tone RBT and outputs it to the originating analog telephone TEL1.

In this state, assume that the user of the terminating analog telephoneTEL4 goes off-hook to answer the call. Then, the analog telephone hubapparatus 3-2 outputs a connection message (connect message; Conn) tothe originating analog telephone hub apparatus 3-1. Upon receiving theconnect message, the originating analog telephone hub apparatus 3-1sends back a connection confirmation message (connect acknowledgementmessage; Conn Ack), and stops the ring back tone.

In this way, a voice communication connection is established on the LAN1, and a voice communication can be made between the originating analogtelephone TEL1 and the terminating analog telephone TEL4 via acommunication link based on this voice connection.

During the voice communication, the analog telephone hub apparatuses 3-1and 3-2 convert audio data. More specifically, an audio packet receivedfrom the LAN 1 is converted into an analog audio signal corresponding tothe analog telephone TEL1 by the packet converter 3 k and audio signalconverter 3 j, and the converted analog audio signal is sent to theanalog telephone TEL1 or TEL4 via the analog telephone I/F 3 b. An audiosignal sent from the analog telephone TEL1 or TEL4 is converted into adigital signal by the audio signal converter 3 j and is converted intoan audio packet by the packet converter 3 k, and the audio packet istransmitted from the network I/F 3 a onto the LAN 1.

Assume that the voice communication has ended, and the user of, e.g.,the analog telephone TEL4 goes on-hook. The analog telephone hubapparatus 3-2 generates a disconnection message (Disc) and sends it ontothe LAN 1 toward the analog telephone hub apparatus 3-1 on thecommunication partner side. Upon receiving the disconnection message,the analog telephone hub apparatus 3-1 stops transmission/reception ofan audio packet on the LAN 1 and releases the voice connection. Then,the apparatus 3-1 sends a release message (Rel) to the analog telephonehub apparatus 3-2 on the other end of the line, and outputs a busy toneto the analog telephone TEL1. In this state, when the apparatus 3-1receives a release acknowledgement message (Rel Comp) from the analogtelephone hub apparatus 3-2 on the other end of the line, the apparatus3-1 stops output of the busy tone and returns to a standby state.

Note that the router apparatus 5 may be inquired of as to the IPaddress. FIG. 12 shows the operation sequence in such case.

The router apparatus 5 stores an IP address in its own destinationdatabase 5 h together with the DN of the terminating terminal apparatusevery time each hub apparatus in the system acquires an IP address usinga multi-address request. More specifically, when a given hub apparatusin the system multi-address transmits a request message of an IPaddress, and another hub apparatus sends back a request response messageto this request, the router apparatus 5 also receives this requestresponse message. The apparatus 5 extracts the DN of the terminatingterminal apparatus and the IP address of the hub apparatus that servesthe terminal apparatus of interest, and stores them in its owndestination database 5 h in correspondence with each other. Hence, thecontents of the destination database 5 h of the router apparatus 5 growrich as IP addresses are acquired using multi-address requests by thehub apparatuses in the system.

Assume that the user of, e.g., a telephone TELi connected to a hubapparatus 3 i (not shown) places a call to the telephone TEL4. The hubapparatus 3i generates a request message containing DN “1010” of theterminating telephone TEL4, and outputs it toward the router apparatus5.

Upon receiving the request message, the router apparatus 5 reads out theIP address of a hub apparatus that serves the communication terminalcorresponding to DN “1010” contained in this request message from thedestination database 5 h using that DN as a key. The apparatus 5 insertsthe readout IP address in a request response message, and sends themessage to the hub apparatus 3 i that is the request source.

Upon receiving the request response message, the hub apparatus 3 itransmits a setup message including as a destination address the IPaddress informed by the received message toward the terminating analogtelephone hub apparatus 3-2. The hub apparatus 3-2 on the terminatingside analyzes this setup message, and outputs a call termination signalto the terminating telephone TEL4 to signal reception of an incomingcall. Also, the apparatus 3-2 outputs a ringer signal to the originatinghub apparatus 3 i to generate a ring back tone(RBT) from the originatingtelephone TELi. When the user of the terminating telephone TEL4 answersthe call, both the telephones TELi and TEL4 are ready for the users totalk.

Note that the IP address acquisition/storage function using themulti-address request of the hub apparatus may be provided to all orsome of the hub apparatuses 3-1, 3-2, 3-i, . . . in place of the routerapparatus 5. In a system in which the hub apparatuses 3-1, 3-2, 3-i, . .. have such function, when a terminal apparatus served by the ownapparatus places a call, each of the hub apparatuses 3-1, 3-2, 3-i, . .. searches its own destination database 3 h to check if the IP addressof the terminating hub apparatus is stored. If the IP address is stored,the originating hub apparatus outputs a setup message to the terminatinghub apparatus using the stored address as a destination address. Bycontrast, if the IP address is not stored, 5 the originating hubapparatus inquires of the communication server 9 or router apparatus 5about the IP address. With this process, the time required for acquiringthe IP address can be shortened, and an increase in traffic on the LAN 1can be suppressed.

(3) When extension-to-extension voice communication is made betweenanalog telephone and personal computer

FIG. 13 shows the sequence. A case will be exemplified below wherein theuser of the analog telephone TEL1 assigned dial number 1000 places acall to the personal computer PC1 assigned dial number 2000.

Assume that the user of the analog telephone TEL1 lifts its handset anddial-inputs dial number “2000” of the communication partner after he orshe has confirmed a dial tone. The analog telephone hub apparatus 3-1performs dial analysis of the terminating apparatus to acquire the IPaddress of the terminating hub apparatus after it has received all thedigits of the dial number from the analog telephone TEL1. Note that theIP address is acquired by the same scheme as that. described in (2) whenan extension-to-extension communication is made between analogtelephones.

After the IP address of the terminating personal computer PC1 isacquired, the analog telephone hub apparatus 3-1 generates a setupmessage and transmits it toward the terminating personal computer PS1.This setup message is received by the personal computer PC1 via the hubapparatus 70. Upon receiving the setup message, the personal computerPC1 sends back a call setup acceptance (call proc) to the originatinghub telephone hub apparatus 3-1, determines based on the received setupmessage if the data type is audio, and stores the result. If the datatype is audio, the personal computer PC1 audibly outputs a callreception message to inform the user of reception of an incoming call.At the same time, the personal computer PC1 outputs a ringer signal(Alert) to the originating analog telephone hub apparatus 3-1.

Upon receiving the ringer signal, the originating analog telephone hubapparatus 3-1 generates a ring back tone RBT and outputs it to theoriginating analog telephone TEL1. In this state, assume that the userof the terminating personal computer PC1 makes operation correspondingto off-hook to answer the call. Then, the personal computer PC1 outputsa connection message (connect message; Conn) to the originating analogtelephone hub apparatus 3-1. Upon receiving the connect message, theoriginating analog telephone hub apparatus 3-1 sends back a connectionconfirmation message (connect acknowledgement message; Conn Ack) andstops the ring back tone.

In this way, a voice communication connection is established on the LAN1, and the users of the originating analog telephone TEL1 and theterminating personal computer PC1 can talk via the communication linkbased on this voice communication connection.

During this voice communication, audio data conversion between the LAN 1and analog telephone TEL1 is made by the analog telephone hub apparatus3-1, but that between the LAN 1 and the audio system of the personalcomputer PC1 is made inside the personal computer PC1. That is, the hubapparatus 70 for the personal computer only interfaces between thepersonal computer PC1 and LAN 1.

(4) When extension-to-extension voice communication is made betweenpersonal computers

FIG. 14 shows the sequence. A case will be exemplified below wherein theuser of the personal computer PC1 assigned dial number 2000 places acall to another personal computer PCi (not shown) assigned dial number2010.

When the user inputs a call originating instruction to dial number 2010at the personal computer PC1, the personal computer PC1 makes dialanalysis to acquire the IP address of the terminating hub apparatus.Note that the IP address is acquired by the same scheme as thatdescribed in (2) when an extension-to-extension communication is madebetween analog telephones.

After the IP address of the terminating hub apparatus is acquired, thepersonal computer PC1 generates a setup message and transmits it ontothe LAN 1 toward the terminating personal computer PCi. This setupmessage is received by a hub apparatus to which the terminating personalcomputer PCi is connected via the LAN 1, and is transferred from the hubapparatus PCi to the personal computer PCi.

Upon receiving the setup message, the personal computer PCi sends back acall setup acceptance (cal proc) to the personal computer PC1 on theoriginating side, and checks based on the received setup message if thedata type indicates audio and stores the result. If the data typeindicates audio, a ringing tone is generated to inform the user of thepresence of an incoming call. At the same time, a ringer signal (Alert)is output to the originating personal computer PC1.

In this state, assume that the user of the terminating personal computerPCi makes operation corresponding to off-hook to answer the call. Thepersonal computer PCi then outputs a connection message (connectmessage; Conn) to the originating personal computer PC1.

In this manner, a voice communication connection is established on theLAN 1, and after that, the users of the originating personal computerPC1 and terminating personal computer PCi can talk via a communicationlink based on this voice communication connection.

During this voice communication, audio data conversion between the LAN 1and the personal computers PC1 and PCi is respectively made inside thepersonal computers PC1 and PCi.

(5) When extension-to-extension data communication is made betweenpersonal computers

FIG. 15 shows the sequence. The personal computer PC1 on the originatingside acquires the IP address assigned to a hub apparatus on theterminating side, and then transmits a connect message onto the LAN 1toward the terminating personal computer PCi. After transmission of theconnect message, the personal computers PC1 and PCi perform processingfor establishing a TCP/IP connection. After the connection has beenestablished by that processing, the personal computers PC1 and PCi areready to make a data communication therebetween.

(6) When voice communication is made between outside-line data terminaland extension analog telephone (if outside-line data terminal caninterpret IP address in LAN 1)

FIG. 16 shows the sequence. A case will be exemplified below wherein anoutside-line data terminal (personal computer) connected to the ISDN 7calls the analog telephone TEL2 assigned dial number “85-3296” to make avoice communication.

The outside-line data terminal transmits a setup message inserted withtermination number “85-3296” and data type=non-limited to the ISDNrouter apparatus 5 via the ISDN 7. Then, the ISDN router apparatus 5sends back a call setup acceptance (call proc) to the outside-line dataterminal on the originating side in accordance with the ISDN protocol,and analyzes the received setup message to sequentially output a ringersignal (Alert) and connection message (connect message; Conn) to theoriginating outside-line data terminal on the basis of the analysisresult. In this manner, a communication connection according to the ISDNprotocol is established between the outside-line data terminal and ISDNrouter apparatus 5.

After the ISDN communication connection has been established in thisway, the originating outside-line data terminal generates in turn asetup message including the IP address assigned from the system to theterminating analog hub apparatus 3-1, and data type=audio, and transmitsit toward the ISDN router apparatus 5 in accordance with the protocol(H.323) of the LAN 1. Upon receiving the setup message, the ISDN routerapparatus 5 directly outputs it onto the LAN 1 toward the terminatinganalog telephone hub apparatus 3-1.

Upon receiving the setup message addressed to the own apparatus, theanalog telephone hub apparatus 3-1 on the terminating side sends back acall setup acceptance (call proc) toward the outside-line data terminalon the originating side, and analyzes the received setup message. Theapparatus 3-1 sends back a call termination signal to the terminatinganalog telephone TEL2 on the basis of the analysis result to make it tosignal reception of an incoming call. At that time, the apparatus 3-1outputs a ringer signal (Alert) to the originating outside-line dataterminal via the ISDN router apparatus 5.

In this state, assume that the user of the terminating analog telephoneTEL2 goes off-hook to answer the call. Then, the analog telephone hubapparatus 3-1 outputs a connection message (connect message; Conn) tothe originating outside-line data terminal via the ISDN router apparatus5. Upon receiving the connect message, the originating outside-line dataterminal sends back a connection confirmation message (connectacknowledgement message; Conn Ack).

In this way, a communication connection according to the protocol(H.323) of the LAN 1 is established between the outside-line dataterminal and the terminating analog telephone TEL2, and the users of theoriginating outside-line data terminal and terminating analog telephoneTEL2 can talk via a communication link based on that communicationconnection.

Note that in a disconnection procedure after the end of the voicecommunication, the communication connection according to the protocol(H.323) of the LAN 1 is released, and after that, the communicationconnection according to the ISDN protocol is released in the orderopposite to the above-mentioned setup procedure of the communicationlink.

(7) When voice communication is made between outside-line data terminaland extension analog telephone (if outside-line data terminal caninterpret only global IP address of ISDN router apparatus 5) FIG. 17shows the sequence. Referring to FIG. 17, the originating outside-linedata terminal transmits a setup message containing the IP address of therouter to the ISDN router apparatus 5 according to the protocol (H.323)of the LAN 1 while a communication connection according to the ISDNprotocol is established between itself and the ISDN router apparatus 5.

Upon receiving this setup message, the ISDN router apparatus 5 acquiresthe IP address of the terminating analog telephone hub apparatus 3-1 bysearching its own database 5 h, and transmits a setup message onto theLAN 1 toward the analog telephone hub apparatus 3-1 using the acquiredIP address. At this time, extension dial number “3296” of theterminating analog telephone TEL2 and data type are inserted in thatsetup message.

Note that the procedure to be executed between the external dataterminal and terminating analog telephone TEL2 are the same as thatdescribed previously with reference to FIG. 16.

(8) When data communication is made between outside-line data terminaland extension data terminal

FIG. 18 shows the sequence. Referring to FIG. 18, a procedure forestablishing an ISDN communication connection is executed between theoriginating external data terminal and the ISDN router apparatus 5.After the ISDN communication connection has been established, theexternal data terminal transmits a connect message to an extension dataterminal. Upon transmission of this connect message, the originatingexternal data terminal and terminating internal data terminal performprocessing for establishing a TCP/IP connection. After a communicationconnection according to the protocol of the LAN 1 has been establishedbetween the originating external data terminal and terminating internaldata terminal, they can make a data communication.

(9) When voice communication is made between analog telephone andexternal telephone

FIG. 19 shows the sequence. A case will be exemplified below wherein theanalog telephone TEL1 originates a call to an external telephone via theISDN 7 to start a voice communication.

Upon receiving the dial number of an external telephone from the analogtelephone TEL1, the analog telephone hub apparatus 3-1 searches thedestination database in its own apparatus to acquire the IP address ofthe ISDN router apparatus 5. After that, the apparatus 3-1 generates asetup message and transmits it onto the LAN 1 toward the ISDN routerapparatus 5. At this time, the dial number of the terminating externaltelephone and data type=audio are inserted into that setup message. Thissetup message is transferred from the ISDN router apparatus 5 to theterminating external telephone via the ISDN 7.

Upon receiving the setup message addressed to the own apparatus, theterminating external telephone sends back a call setup acceptance (callproc) to the ISDN router apparatus 5, and outputs a ringer signal(Alert) to the originating analog telephone hub apparatus 3-1. Uponreceiving the ringer signal, the originating analog telephone hubapparatus 3-1 generates a ring back tone RBT and outputs it to theoriginating analog telephone TEL1.

Assume that the user of the terminating external telephone goes off-hookin this state to answer the call. Then, the external telephone outputs aconnection message (connect message; Conn) to the originating analogtelephone hub apparatus 3-1 via the ISDN router apparatus 5. Uponreceiving this connect message, the originating analog hub apparatus 3-1sends back a connection confirmation message (connect acknowledgementmessage; Conn Ack) via the ISDN router apparatus 5 and stops the ringback tone.

In this fashion, a voice connection is established between theoriginating analog telephone TEL1 and external telephone via the ISDN 7,and the users of these terminals can talk via a voice communication linkbased on this voice connection.

(10) When voice communication is made between an extension analogtelephone and external telephone (multi-address request scheme).

FIG. 20 shows the sequence. Upon receiving a dial number from theoriginating analog telephone TEL1, the analog telephone hub apparatus3-1 transmits a request message to all the routers connected to the LAN1, i.e., the ISDN router apparatus 5 and PSTN router apparatus 6. Uponreception of this request message via the LAN 1, all the routerapparatuses 5 and 6 connected to the LAN 1 check if a call can be placedto an external telephone corresponding to DN contained in that requestmessage. If a call can be placed, the apparatuses send back a requestmessage indicating this to the analog telephone hub apparatus 3-1 as arequest source. If a call cannot be placed to an external telephonecorresponding to the requested DN, no response message is sent back.

If a request response message is sent back from, e.g., the ISDN routerapparatus 5 in response to the request, the analog telephone hubapparatus 3-1 generates a setup message and sends it back toward theexternal telephone via the ISDN router apparatus 5.

(11) When voice communication is made between an extension analogtelephone and external telephone (server inquiry scheme)

FIG. 21 shows the sequence. Upon receiving the dial number from theoriginating analog telephone TEL1, the analog telephone hub apparatus3-1 transmits an inquiry message to the communication server 9 connectedto the LAN 1. Upon reception of this inquiry message, the server 9accesses the destination database on the basis of the inquiry message toretrieve the IP address of the terminating hub apparatus. Then, theserver 9 informs the analog telephone hub apparatus 3-1 as the inquirysource of that IP address using a response message. Upon receiving theIP address message, the analog telephone hub apparatus 3-1 generates asetup message and transmits it to the ISDN router apparatus 5. The ISDNrouter apparatus 5 transfers this setup message to the externaltelephone.

(12) When voice communication is made between extension analog telephoneand outside-line data terminal

FIG. 22 shows the sequence. Referring to FIG. 22, assume that the usergoes off-hook at the analog telephone TEL1 and dial-inputs dial number“03-3502-9677” of the communication partner after he or she hasconfirmed a dial tone. Then, the analog telephone hub apparatus 3-1performs dial analysis to acquire the IP address of the ISDN routerapparatus 5 from its own destination database 3 h upon receiving all thedigits of the dial number from the analog telephone TEL1.

After the IP address of the ISDN router apparatus 5 is acquired, theanalog telephone hub apparatus 3-1 generates a setup message andtransmits it toward the ISDN router apparatus 5. Upon reception of thissetup message, the ISDN router apparatus 5 sends back a call setupacceptance (call proc) to the originating analog telephone hub apparatus3-1, and transmits a setup message in which termination number“03-3502-9677” and data type=non-limited are inserted in accordance withthe ISDN protocol to an outside-line data terminal via the ISDN 7. Theoutside-line data terminal sends back a call setup acceptance (callproc) to the ISDN router apparatus 5 in accordance with the ISDNprotocol, and outputs a ringer signal (Alert) and connection message(connect message; Conn) in turn. In this way, a communication connectionaccording to the ISDN protocol is established between the ISDN routerapparatus 5 and outside-line data terminal.

After the ISDN communication connection has been established, the ISDNrouter apparatus 5 generates a setup message that contains the IPaddress assigned to the external data terminal and data type=audio, andtransmits it toward the external data terminal in accordance with theprotocol (H.323) of the LAN 1. Upon receiving the setup message, theexternal data terminal sends back a call setup acceptance (call proc)toward the originating ISDN router apparatus 5, and also outputs aringer signal (Alert). This ringer signal is transferred from the ISDNrouter apparatus 5 to the analog telephone hub apparatus 3-1 via the LAN1. Upon receiving this ringer signal, the analog telephone hub apparatus3-1 generates a ring back tone and transmits it to the originatinganalog telephone TEL1.

In this state, if the user makes operation corresponding to off-hook atthe terminating external data terminal to answer the call, the externaldata terminal outputs a connection message (connect message; Conn) tothe originating analog telephone hub apparatus 3-1 via the ISDN routerapparatus 5. Upon reception of this connect message, the originatinganalog telephone hub apparatus 3-1 sends back a connection confirmationmessage (connect acknowledgement message; Conn Ack).

In this way, a communication connection according to the protocol(H.323) of the LAN 1 is established between the originating analogtelephone TEL1 and terminating external data terminal, and the users ofthe originating analog telephone TEL1 and terminating external dataterminal can talk via a communication link based on this communicationconnection.

Note that in a disconnection procedure after the end of the voicecommunication, the communication connection according to the protocol(H.323) of the LAN 1 is released, and after that, the communicationconnection according to the ISDN protocol is released in the orderopposite to the above-mentioned setup procedure of the communicationlink.

(13) When data communication is made between extension data terminal andoutside-line data terminal

FIG. 23 shows the sequence. Referring to FIG. 23, the originatingextension data terminal transmits a connect message to the ISDN routerapparatus 5 in accordance with the TCP/IP protocol. Upon receiving thisconnect message, the ISDN router apparatus 5 executes a procedure forestablishing an ISDN communication connection between itself and theexternal data terminal. After the ISDN communication connection has beenestablished, the ISDN router apparatus 5 transmits a connect message tothe external data terminal in accordance with the TCP/IP protocol.

Upon transmission of this connect message, the originating extensiondata terminal and terminating external data terminal perform processingfor establishing a TCP/IP connection. After the communication connectionaccording to the protocol of the LAN 1 has been established between theoriginating extension data terminal and terminating external dataterminal, a data communication can be made between the originatingextension data terminal and terminating external data terminal.

(14) When extension terminal accesses outside line (router apparatusdetermines terminating apparatus on the basis of its own database)

In the following description, as shown in, e.g., FIG. 24, hubapparatuses H1, H2, and H3, and the router apparatus 5 are respectivelyassigned IP addresses “IP: 133.114.131.100”, “IP: 133.114.131.101”, “IP:133.114.131.102”, and “IP: 133.114.131.200”, and extension terminalsTM1, TM2, and TM3 served by the hub apparatuses H1, H2, and H3 areassigned extension telephone numbers DN “DN: 3000”, “DN: 3001”, and “DN:3002”. Furthermore, an outside-line terminal Tm1 connected to the routerapparatus 5 via the ISDN 7 is assigned subscriber's telephone number“DN: 03-1234-5678”.

Referring to FIG. 25, when the extension terminal TM1 outputs a calloriginating request to the outsi-deline terminal TMi, the hub apparatusH1 inserts destination DN “03-1234-5678” into an inquiry signal (requestmessage) together with source DN “3000”, and transmits that signal ontothe LAN 1 toward the router apparatus 5.

The router apparatus 5 comprises a database that stores thecorrespondences between the DNs of all the extension terminals served bythe system, and the IP addresses of the hub apparatuses that serve theextension terminals, as shown in, e.g., FIG. 26. Upon receiving therequest message from the hub apparatus, it is checked if the destinationDN contained in that request message is stored in the database. If thedestination DN is stored, it is determined that the terminatingapparatus is an extension terminal; otherwise, it is determined that theterminating apparatus is an outside-line terminal. In this case, sincethe destination DN sent from the hub apparatus H1 is the subscriber'stelephone number of an outside-line terminal, the router apparatus 5determines that the terminating apparatus is an outside-line terminal,and sends back a response signal (request response message) insertedwith its own IP address “IP: 133.114.131.200” to the hub apparatus H1 asthe inquiry source.

If the terminating apparatus is an extension terminal, the routerapparatus 5 searches the database using the DN of that terminatingextension terminal as a key, inserts the IP address of the hub apparatusthat serves the terminating extension terminal into a response signal(request response message), and sends it back to the hub apparatus H1 asthe inquiry source.

When the hub apparatus H1 acquires the IP address of the routerapparatus 5 from the request response message, it transmits a calloriginating signal (setup signal) to the router apparatus 5 using thatIP address as a destination address. Upon receiving the setup message,the router apparatus 5 transmits the call originating signal onto theISDN 7. Upon reception of the call originating signal, the ISDN 7outputs a call termination signal to the terminating terminal TMi tomake it generate a ringing tone.

When the user of the terminating terminal TMi answers the call, thatresponse is transmitted to the ISDN 7, thus forming a communication linkbetween the terminating terminal TMi and router apparatus 5. Then, theresponse is transferred from the router apparatus 5 to the hub apparatusH1, thus forming a communication link between the originating extensionterminal TM1 and terminating terminal TMi and allowing a communicationsuch as a voice communication between the two terminals TM1 and TMi.

(15) When extension terminal accesses outside line (router apparatusdetermines terminating apparatus on the basis of special service code)

FIG. 27 is a sequence chart showing the call originating process. Wheneach of the extension terminals TM1, TM2, and TM3 accesses an outsideline, it appends a special service code indicating outside line accessto the subscriber's telephone number of the partner apparatus, andtransmits them. For example, when the extension terminal TM1 originatesa call to the outside-line terminal TMi, it appends special service code“0” to subscriber's telephone number “DN: 03-1234-5678” of the partnerterminal TMi, and transmits them.

Upon receiving the call originating request from the extension terminalTM1, the hub apparatus H1 inserts special service code “0” anddestination DN “03-1234-5678” contained in that call originating requestinto a request message together with source DN “3000”, and transmits themessage onto the LAN 1 toward the router apparatus 5.

Upon reception of the request message from the hub apparatus H1, therouter apparatus 5 checks based on the presence/absence of specialservice code “0” in the request message if the terminating apparatus isan extension terminal or outside-line terminal. In this case, since therequest message contains special service code “0”, the router apparatus5 determines that the terminating apparatus is an outside-line terminal,inserts its own IP address “IP: 133.114.131.200” into a request responsemessage, and sends back that message to the hub apparatus H1 as theinquiry source.

If the request message does not contain any special service code “0” andit is determined that the terminating apparatus is an extensionterminal, the database is searched using the DN of the terminatingextension terminal as a key, the IP address of the hub apparatus thatserves the terminating extension terminal is inserted into the requestmessage, and the message is sent back to the hub apparatus H1 as theinquiry source.

The operation after the IP address of the router apparatus 5 is informedby the request response message is the same as that described in case(14) above. After a communication link is formed between the originatingextension terminal TM1 and terminating external terminal TMi, acommunication can be made between these terminals.

(16) When extension terminal accesses outside line (content server 9determines terminating apparatus based on its own database)

FIG. 28 is a sequence chart showing that operation. Referring to FIG.28, when the extension terminal TM1 outputs a call originating requestto the outside-line terminal TMi, the hub apparatus H1 insertsdestination DN “03-1234-5678” contained in that call originating requestinto a request message together with DN “3000” of the source extensionterminal TM1, and transmits that message onto the LAN 1 toward thecontent server 9.

The content server 9 comprises a database that stores thecorrespondences between the DNs of all the extension terminals in thesystem, and the IP addresses of the hub apparatuses that serve theextension terminals, as shown, e.g., FIG. 29. Note that this databasealso stores the IP address of the router apparatus 5 in correspondencewith its DN. Upon reception of the request message from the hubapparatus Hi, it is checked if the destination DN contained in thatrequest message is stored in the database. If the destination DN isstored, it is determined that the terminating apparatus is an extensionterminal; otherwise, it is determined that the terminating apparatus isan outside-line terminal.

In this case, since the destination DN sent from the hub apparatus H1 issubscriber's telephone number “DN: 03-1234-5678” of the outside-lineterminal, the content server 9 determines that the terminating apparatusis an outside-line terminal, inserts IP address “IP: 133.114.131.200”into a request response message, and sends back it to the hub apparatusH1 as the inquiry source.

When the destination DN is stored in the database and it is determinedthat the terminating apparatus is an extension terminal, the contentserver 9 searches the database using the DN of the terminating extensionterminal as a key, inserts the IP address of a hub apparatus that servesthe terminating extension terminal into a request response message, andsends back that message to the hub apparatus HI as the inquiry source.

When the hub apparatus Hi acquires the IP address of the routerapparatus 5 from the request response message, it transmits a setupmessage to the router apparatus 5 using that IP address as a destinationaddress. Upon receiving the setup message, the router apparatus 5transmits a call originating signal onto the ISDN 7. Upon reception ofthe call originating signal, the ISDN 7 outputs a call originatingsignal to the terminating terminal TMi to make it output a ringing tone.

When the user of the terminating terminal TMi answers the call, theresponse is transmitted to the ISDN 7, thereby forming a communicationlink between the terminating external terminal TMi and router apparatus5. Furthermore, since the response is supplied from the router apparatus5 to the hub apparatus H1, a communication link is also formed betweenthe originating extension terminal TM1 and terminating terminal TMi,thus allowing a communication such as a voice communication betweenthese terminals TM1 and TMi.

(17) When extension terminal accesses outside line (content serverdetermines terminating apparatus based on special service code)

FIG. 30 is a sequence chart showing that call originating process. Wheneach of the extension 5 terminals TM1, TM2, and TM3 accesses an outsideline, it appends a special service code indicating outside line accessto the subscriber's telephone number of the partner apparatus, andtransmits them. For example, when the extension terminal TM1 originatesa call to the outside-line terminal TMi, it appends special service code“0” to subscriber's telephone number “DN: 03-1234-5678” of the partnerterminal TMi, and transmits them.

Upon receiving the call originating request from the extension terminalTM1, the hub apparatus H1 inserts special service code “0” anddestination DN “03-1234-5678” contained in that call originating requestinto a request message together with source DN “3000”, and transmits themessage onto the LAN 1 toward the content server 9.

Upon reception of the request message from the hub apparatus Hi, thecontent server 9 checks based on the presence/absence of special servicecode “0” in the request message if the terminating apparatus is anextension terminal or outside-line terminal. In this case, since therequest message contains special service code “0”, the content server 9determines that the terminating apparatus is an outside-line terminal,inserts its own IP address “IP: 133.114.131.200” of the router apparatus5 into a request response message, and sends back that message to thehub apparatus Hi as the inquiry source.

If the request message does not contain any special service code “0” andit is determined that the terminating apparatus is an extensionterminal, the database is searched using the DN of the terminatingextension terminal as a key, the IP address of the hub apparatus thatserves the terminating extension terminal is inserted into the requestmessage, and the message is sent back to the hub apparatus H1 as theinquiry source.

The operation after the IP address of the router apparatus 5 is informedby the request response message is the same as that which has beendescribed in case (16) above.

(18) When extension terminal accesses outside line (hub apparatusdetermines terminating apparatus based on database)

FIG. 31 is a sequence chart showing that operation. Referring to FIG.31, when the extension terminal TM1 outputs a call originating requestto the outside-line terminal TMi, the hub apparatus H1 determines theterminating apparatus on the basis of the destination DN contained inthat call originating request.

More specifically, each of the hub apparatuses Hi, H2, H3, . . . , has adatabase that stores the correspondence between the DNs of all theextension terminals in the system, and the IP addresses of the hubapparatuses that serve the extension terminals, as shown in, e.g., FIG.32. Note that this database also stores the IP address of the routerapparatus 5 in correspondence with its DN. Upon receiving the calloriginating request from the extension terminal TM1 served by itself,the hub apparatus checks if the destination DN contained in that calloriginating request is stored in the database. If the destination DN isstored, it is determined that the terminating apparatus is an extensionterminal; otherwise, it is determined that the terminating apparatus isan outside-line terminal.

In this case, since subscriber's telephone number “DN: 03-1234-5678” ofan external terminal is sent from the originating extension terminalTM1, the hub apparatus H1 determines that the terminating apparatus isan outside-line terminal. The hub apparatus H1 reads out IP address “IP:133.114.131.200” of the router apparatus 5 from its own database, andoutputs a setup message to the router apparatus 5 using this IP addressas a destination address.

When the destination DN is stored in its own database and it isdetermined that the terminating apparatus is an extension terminal, thehub apparatus H1 searches the database using the DN of that terminatingextension terminal as a key to read out the IP address of a hubapparatus that serves the terminating extension terminal. Then, the hubapparatus transmits a setup message to the terminating hub apparatususing the IP address as a destination address.

Upon reception of the setup message, the router apparatus 5 transmits acall originating signal to the ISDN 7 on the basis of the information ofthe setup message. Upon reception of the call originating signal, theISDN 7 outputs a call originating signal to the terminating terminal TMito make it output a ringing tone.

When the user of the terminating terminal TMi answers the call in thisstate, the response is supplied to the ISDN 7, thereby forming acommunication link between the terminating external terminal TMi androuter apparatus 5. Furthermore, since the response is transferred fromthe router apparatus 5 to the hub apparatus H1, a communication link isalso formed between the originating extension terminal TM1 andterminating terminal TMi, thus allowing a communication such as a voicecommunication or the like between these terminals TM1 and TMi.

(19) When extension terminal accesses outside line (hub apparatusdetermines terminating apparatus based on special service code)

FIG. 33 is a sequence chart showing that operation. When each of theextension terminals TM1, TM2, and TM3 accesses an outside line, itappends a special service code indicating outside-line access to thesubscriber's telephone number of the partner apparatus and transmitsthem. For example, when the extension terminal TM1 originates a call tothe outside-line terminal TMi, it appends special service code “0” tosubscriber's telephone number “DN: 03-1234-5678” of the partner terminalTMi and transmits them.

Upon receiving a call originating request from this extension terminalTM1, the hub apparatus H1 checks if special service code “0” is appendedto destination information contained in that call originating request.If the special service code is appended, the hub apparatus determinesthat the terminating apparatus is an external terminal, reads out IPaddress “IP: 133.114.131.200” of the router apparatus 5 from its owndatabase, and transmits a setup message to the router apparatus 5 usingthis IP address as a destination address.

The operation after the setup message is sent from the hub apparatus H1to the router apparatus 5 is the same as that which has been describedin case (18) above.

(20) When call is received from external terminal to extension terminal(scheme for determining terminating apparatus based on sub-address) FIG.34 is a sequence chart showing that operation. Assume that at, e.g., theexternal terminal TMi, the user places a call to the extension terminalTM1 served by the system of this embodiment having the LAN 1 as a core.In this case, the external terminal TMi transmits a call originatingsignal in which a subscriber's telephone number (e.g., “DN:0231-89-1234”) assigned to this system and a sub-address (e.g., “1”)that designates the terminating extension terminal TM1 are inserted asdestination information. Upon receiving this call originating signal,the ISDN 7 transmits a call terminating signal containing the abovedestination information as destination information toward this system.

The call originating signal coming from the ISDN 7is received by therouter apparatus 5. The router apparatus 7 has a sub-address databasethat stores the DNs of the extension terminals TM1, TM2, TM3, . . . incorrespondence with sub-addresses “1”, “2”, “3”, . . . , as shown in,e.g., FIG. 35.

Upon reception of the call terminating signal, the router apparatus 5extracts the sub-address from that destination information, and searchesthe sub-address database using the sub-address as a key, thereby readingout the DN of the terminating extension terminal. For example, if thesub-address is “1”, “DN: 3000” is read out from the sub-addressdatabase, as can be seen from FIG. 35. Then, the router apparatus 5accesses the IP address search database shown in FIG. 26 previouslyusing the readout DN as a key, thus reading out the IP address of thehub apparatus H1 that serves the terminating extension terminal TM1. Therouter apparatus 5 generates a call terminating message using this IPaddress as a destination address, and transmits the call terminatingmessage to the terminating hub apparatus H1.

Upon receiving the call terminating message, the hub apparatus H1outputs a call terminating signal to the extension terminal TM1corresponding to the extension DN (DN: 3000) contained in thatdestination information to make it generate a ringing tone.

In this state, when the user answers the call at the extension terminalTM1, that response message is sent to the hub apparatus Hi, and is thentransferred from the hub apparatus H1 to the router apparatus 5. In thisway, a communication link is formed between the router apparatus 5 andterminating extension terminal TM1. Furthermore, the response message issent from the router apparatus 5 to the ISDN 7. As a consequence, acommunication link is formed between the originating external terminalTMi and terminating internal terminal TM1, thus allowing a communicationbetween these terminals.

(21) When call to extension terminal is received from external terminal(scheme for determining terminating apparatus based on communicationtype expressed by sub-address)

FIG. 36 is a sequence chart showing that operation. The externalterminal TMi has a function of generating a sub-address corresponding tocommunication type. When the user at the external terminal TMi places acall to the extension terminal TM1, the external terminal TMi generatesdestination information that contains a subscriber's telephone number(for example, “DN: 0231-89-1234”) assigned to the terminating system,and a sub-address corresponding to the communication type to be madenow, and transmits a call originating signal containing this destinationinformation toward the ISDN 7. For example, assuming that the user wantsto make a voice communication now, sub-address “1” indicating that thecommunication type is a voice communication is inserted into thedestination information to be transmitted. On the other hand, if theuser wants to make a data communication, sub-address “2” indicating thatthe communication type is a data communication is inserted into thedestination information to be transmitted.

A call terminating signal coming from the ISDN 7 is received by therouter apparatus 5. The router apparatus 7 has a communication typedatabase that stores the communication types corresponding tosub-addresses, and the DNs of the extension terminals corresponding tothese communication types.

Upon receiving the call terminating signal, the router apparatus 5extracts a sub-address from that destination information, and searchesthe communication type database using the sub-address as a key, thusreading out the DN of the extension terminal corresponding to thecommunication type requested by the originating external terminal TMi.Assuming that, for example, the received sub-address is “1”, thecommunication type requested by the originating external terminal TMi is“voice communication”, and the DN of an extension terminal (e.g., “DN:3000” of the telephone TM1) such as a telephone capable of “voicecommunication” is read out from the communication type database. On theother hand, if the received sub-address is “2”, the communication typerequested by the originating external terminal TMi is “datacommunication”, and the DN of an extension terminal (e.g., “DN: 3001” ofthe personal computer TM2” such as a personal computer or the likecapable of “data communication” is read out from the communication typedatabase.

The router apparatus 5 then accesses the IP address search databaseshown in FIG. 26 previously using the readout DN as a key, thus readingout the IP address of a hub apparatus that serves the terminatingextension terminal. After that, the router apparatus 5 generates a callterminating message using the IP address as a destination address, andtransmits that call terminating message to the terminating hubapparatus.

The system operation after the call terminating message is sent to thehub apparatus is the same as that which has been described in case (20)above.

In this manner, in the aforementioned operation mode, when anoriginating external terminal has a function of automatically appendinga sub-address that represents the communication type to destinationinformation to be transmitted, the router apparatus 5 comprises acommunication type database that stores sub-addresses to be received andthe DNs of extension terminals corresponding to communication typesrepresented by the sub-addresses. When the router apparatus 5 accessesthis database using the received sub-address as a key, an extensionterminal corresponding to the communication type requested by theoriginating external terminal is selected, and the selected extensionterminal is controlled to receive that call.

With this control, an originating terminal need only designate anarbitrary communication type upon originating a call, and an extensionterminal corresponding to the designated communication type isautomatically selected to receive the call. For this reason, the user onthe originating side need not designate a terminating extension terminalin correspondence with the communication types in units of calls, andcan very easily originate a call of his or her desired communicationtype.

(22) When call to extension terminal is received from external terminal(scheme for determining terminating apparatus based on originatingapparatus DN)

FIG. 38 is a sequence chart showing that operation. When the user of theexternal terminal TMi places a call to the extension terminal TM1, theexternal terminal TMi generates destination information containing onlya subscriber's telephone number (e.g., “DN: 0231-89-1234”) assigned tothe terminating system, and transmits a call originating signalcontaining that destination information toward the ISDN 7.

The ISDN 7 manages the subscribers' telephone numbers of all theterminals served by its own network. Upon receiving the call originatingsignal, the ISDN 7 generates a call terminating signal in which thedestination information contained in the call originating signal, andthe subscriber's telephone number of the originating external terminalTMi are inserted, and transmits the call terminating signal to therouter apparatus 5.

The router apparatus 7 has a caller database that stores the DNs of theextension terminals in correspondence with originating apparatus IDs, asshown in, e.g., FIG. 39. Upon receiving the call terminating signalcoming from the ISDN 7, the router apparatus 5 accesses the callerdatabase using the originating apparatus DN inserted in this callterminating signal as a key to read out the DN of the correspondingextension terminal.

Subsequently, the router apparatus 5 first accesses the IP addresssearch database shown in FIG. 26 using the readout DN as a key to readout the IP address of a hub apparatus that serves the terminatingextension terminal. Subsequently, the router apparatus 5 generates acall terminating message using this IP address as a destination address,and transmits the call terminating message to the terminating hubapparatus.

The system operation after the call terminating message is sent to thehub apparatus is the same as that which has been described in case (20)above.

According to this operation mode, when the caller database stores theterminal DNs of callers in correspondence with extension terminals ofcorresponding communication types in advance, a call can always bereceived by an extension terminal that can communicate with the externalterminal that the caller used. Hence, the caller need only originate acall by selecting a desired communication terminal, but can communicatewith an extension terminal of the corresponding communication type. Inthis way, the user on the originating side need not designate aterminating extension terminal in correspondence with the communicationtypes in units of calls, and can very easily originate a call of adesired communication type.

In the above embodiment, various communication methods of the presentinvention have been explained using the functional diagram and sequencecharts that pertain to the respective processes. In the followingembodiment, the operation of the present invention will be explainedusing the detailed arrangements of hub apparatuses, router apparatuses,and the like.

An example of the hub apparatus will be described in detail first.

FIG. 40 is a block diagram showing an embodiment of a hub apparatusaccording to the present invention. The hub apparatus according to oneembodiment of the present invention has a power supply unit 11, currentmonitor 12, ringer output unit 13, hybrid unit 21, CODEC 22, PB receiver23, and tone generator 24. Furthermore, the hub according to the presentinvention comprises a communication memory 31, DMAC_A 32, SIO_A 33, LANinterface 41, SIO_B 42, DMAC_B 43, and CPU 50.

Normally, the power supply unit 11 to ringer output unit 13 are providedto the terminal side. Of these units, the ringer output unit 13 may beprovided to the hub apparatus main body.

The functions of the respective units with the above arrangement are asfollows.

The power supply unit 11 supplies a DC current to a terminal 10 a. Thecurrent monitor 12 monitors the DC current on the line. The ringeroutput unit 13 outputs a ringer signal to the terminal 10 a. The hybridunit 21 performs two-wire/four-wire conversion of analog signals in thevoice channel band. The CODEC 22 encodes or decodes signals. The PBreceiver 23 decodes a PB signal from the terminal 10 a. The tonegenerator 24 generates a call progress tone.

The communication memory 31 saves communication data. The DMAC_A 32transfers encoded data between the communication memory 31 and SIO_A 33.The SIO_A 33 exchanges serial data with the CODEC 22, and exchangesparallel data with the DMAC_A 32. The LAN interface 41 communicates witha LAN 40. The SIO_B 42 exchanges serial data with the LAN interface 41,and exchanges parallel data with the DMAC_B 43. The DMAC_B 43 transferspacketized data between the communication memory 31 and SIO_B 42.

Note that the CPU 50 processes data on the communication memory 31 andcontrols the respective units.

The operation of the hub apparatus with the above-mentioned arrangementwill be explained below.

Formation of a voice channel upon reception of a voice communicationrequest from the LAN 40 will be explained first.

Upon receiving a communication request packet of an originatingapparatus from the LAN 40, the LAN interface 41 transmits the packet tothe SIO_B 42 as serial data. The SIO_B 42 converts the received serialdata into parallel data. The parallel data converted by the SIO_B 42 istransferred to the communication memory 31 by the DMAC_B 43.

Upon completion of transfer to the communication memory 31, the CPU 50analyzes the packet data stored in the communication memory 31. If theCPU 50 determines as a result of analysis that the received packet is acommunication request to the terminal 10 a, it checks the status of theterminal 10 a. If the terminal 10 a is idle, the CPU 50 controls theringer output unit 13 to output a ringer signal to the terminal 10 a soas to receive the call.

If the user of the terminal 10 a answers the call and a DC loop isformed, the current monitor 12 detects the DC current supplied from thepower supply unit 11, and informs the CPU 50 of it. Upon detecting theresponse, the CPU 50 informs the originating apparatus of that messageusing a response packet, and enables the CODEC 22 to form acommunication channel between the originating apparatus and terminal 10a.

Note that the response packet is transmitted to the originatingapparatus as follows. The response packet generated by the CPU 50 isstored in the communication memory 31. The DMAC_B 43 reads out thisresponse packet from the communication memory 31 as parallel data, andtransfers the parallel data to the SIO_B 42. The SIO_B 42 converts theparallel data into serial data, and transmits the serial data to the LANinterface 41. The LAN interface 41 packetizes the serial data inaccordance with the protocol of the LAN 40, and transmits the packet tothe originating apparatus.

A communication method (by means of, e.g., voice) when the voice channelhas been formed in this way is as follows.

When an audio packet obtained by packetizing encoded audio data arrivesat the communication memory 31 from the originating apparatus via theLAN interface 41, SIO_B 42, and DMAC_B 43 after a voice channel isformed, the CPU 50 stores audio data (parallel data) alone in anotherarea of the communication memory 31. The DMAC_A 32 reads out theparallel audio data from the communication memory 31, and transfers thatdata to the SIO_A 33. The SIO_A 33 converts the parallel audio data intoserial audio data, and outputs the serial audio data to the CODEC 22.The audio data is decoded by the CODEC 22, is converted from four-wiredata into two-wire data by the hybrid unit 21, and is then output as ananalog audio signal to the terminal 10 a.

An analog audio signal output from the terminal 10 a is converted fromtwo-wire data into four-wire data by the hybrid unit 21, and is thenoutput from the CODEC 22 as encoded serial data to the SIO_A 33. TheSIO_A 33 converts the serial audio data into parallel audio data, whichis transferred to the communication memory 31 by the DMAC_A 32. Theaudio data from the terminal 10 a stored in the communication memory 31is packetized by the CPU 50, and is stored in another area of thecommunication memory 31. The DMAC_B 43 reads out the audio packet fromthe communication memory 31 as parallel data, and transfers the paralleldata to the SIO_B 42. The SIO_B 42 converts the parallel data intoserial data, and transmits the serial data to the LAN interface 41. TheLAN interface 41 packetizes the serial data in accordance with theprotocol of the LAN 40, and transmits the packet to the originatingapparatus.

A method of forming a communication channel upon receiving a calloriginating request from the terminal 10 a is as follows.

When the user of the terminal 10 a goes off-hook to form a DC loop, thecurrent monitor 12 detects the DC current supplied from the power supplyunit 11, and informs the CPU 50 of it. Upon detecting off-hook of theterminal 10 a, the CPU 50 controls the terminal 10 a to output a dialtone. When the terminal 10 a outputs a selection signal after itconfirms the dial tone, the PB receiver 23 decodes the selection signaland supplies it to the CPU 50. The CPU 50 specifies the terminatingapparatus on the basis of the number of the selection signal, generatesa communication request packet, and transmits the communication requestpacket to the LAN 40 via the communication memory 31, DMAC_B 43, SIO_B42, and LAN interface 41 in the same procedure as that for transmittinga response packet to the originating apparatus, thus supplying therequest packet to the terminating apparatus. Upon receiving a responsepacket from the terminating apparatus, the CPU 50 enables the CODEC 22to form a communication channel between the terminal 10 a andterminating apparatus.

FIG. 41 is a block diagram showing the first modification of the hubapparatus shown in FIG. 40.

The hub apparatus according to the first modification is constructed bya power supply unit 11, current monitor 12, ringer output unit 13,hybrid unit 21, CODEC 22, PB receiver 23, tone generator 24,communication memory 31, DMAC_A 32, SIO_A 33, LAN interface 41, SIO_B42, DMAC_43, CPU 50, and LAN hub 44.

The same reference numerals in FIG. 41 denote the same parts as those inFIG. 40, and a detailed description thereof will be omitted.

In this first modification, the LAN hub 44 is inserted between the LANinterface 41 and LAN 40, and serves a plurality of LAN interfaces 41, sothat a plurality of hub apparatuses can be connected. Note that in FIG.41 another LAN interface 41 connected to the LAN hub 44 is incorporatedin, e.g., a personal computer PC.

The operation of the hub apparatus with the aforementioned arrangementwill be explained below.

Formation of a voice channel upon receiving a voice communicationrequest from the LAN 40 will be explained first.

Upon receiving a communication request packet of an originatingapparatus from the LAN 40 served by the LAN hub 44, the LAN interface 41transmits the packet to the SIO_B 42 as serial data. The SIO_B 42converts the received serial data into parallel data. The parallel dataconverted by the SIO_B 42 is transferred to the communication memory 31by the DMAC_B 43.

Upon completion of transfer to the communication memory 31, the CPU 50analyzes the packet data stored in the communication memory 31. If theCPU 50 determines as a result of analysis that the received packet is acommunication request to the terminal 10 a, it checks the status of theterminal 10 a. If the terminal 10 a is idle, the CPU 50 controls theringer output unit 13 to output a ringer signal to the terminal 10 a soas to receive the call.

If the user of the terminal 10 a answers the call and a DC loop isformed, the current monitor 12 detects the DC current supplied from thepower supply unit 11, and informs the CPU 50 of it. Upon detecting theresponse, the CPU 50 informs the originating apparatus of that messageusing a response packet, and enables the CODEC 22 to form acommunication channel between the originating apparatus and terminal 10a.

Note that the response packet is transmitted to the originatingapparatus as follows. The response packet generated by the CPU 50 isstored in the communication memory 31. The DMAC_B 43 reads out thisresponse packet from the communication memory 31 as parallel data, andtransfers the parallel data to the SIO_B 42. The SIO_B 42 converts theparallel data into serial data, and transmits the serial data to the LANinterface 41. The LAN interface 41 packetizes the serial data inaccordance with the protocol of the LAN 40, and transmits the packet tothe originating apparatus via the LAN hub 44.

A communication method (by means of, e.g., voice) when a voice channelhas been formed in this way is as follows.

When an audio packet obtained by packetizing encoded audio data arrivesat the communication memory 31 from the originating apparatus via theLAN hub 44, LAN interface 41, SIO_B 42, and DMAC_B 43 after a voicechannel is formed, the CPU 50 stores audio data (parallel data) alone inanother area of the communication memory 31. The DMAC_A 32 reads out theparallel audio data from the communication memory 31, and transfers thatdata to the SIO_A 33. The SIO_A 33 converts the parallel audio data intoserial audio data, and outputs the serial audio data to the CODEC 22.The audio data is decoded by the CODEC 22, is converted from four-wiredata into two-wire data by the hybrid unit 21, and is then output as ananalog audio signal to the terminal 10 a.

An analog audio signal output from the terminal 10 a is converted fromtwo-wire data into four-wire data by the hybrid unit 21, and is theoutput from the CODEC 22 as encoded serial data to the SIO_A 33. TheSIO_A 33 converts the serial audio data into parallel audio data, andthe converted parallel data is transferred to the communication memory31 by the DMAC_A 32. The audio data from the terminal 10 a stored in thecommunication memory 31 is packetized by the CPU 50, and is stored inanother area of the communication memory 31. The DMAC_B 43 reads out theaudio packet from the communication memory 31 as parallel data, andtransfers the parallel data to the SIO_B 42. The SIO_B 42 converts theparallel data into serial data, and transmits the serial data to the LANinterface 41. The LAN interface 41 packetizes the serial data inaccordance with the protocol of the LAN 40, and transmits the packet tothe originating apparatus via the LAN hub 44.

A method of forming a communication channel upon receiving a calloriginating request from the terminal 10 a is as follows.

When the user of the terminal 10 a goes off-hook to form a DC loop, thecurrent monitor 12 detects the DC current supplied from the power supplyunit 11, and informs the CPU 50 of it. Upon detecting off-hook of theterminal 10 a, the CPU 50 controls the terminal 10 a to output a dialtone. When the terminal 10 a outputs a selection signal after itconfirms the dial tone, the PB receiver 23 decodes the selection signaland supplies it to the CPU 50. The CPU 50 specifies the terminatingapparatus on the basis of the number of the selection signal, generatesa communication request packet, and transmits the communication requestpacket to the LAN 40 via the communication memory 31, DMAC_B 43, SIO_B42, LAN interface 41, and LAN hub 44 in the same procedure as that fortransmitting a response packet to the originating apparatus, thussupplying the request packet to the terminating apparatus. Uponreceiving a response packet from the terminating apparatus, the CPU 50enables the CODEC 22 to form a communication channel between theterminal 10 a and terminating apparatus.

In the first modification, the LAN hub 44 can serve a PC 45 (personalcomputer) having the LAN interface 41, and the PC 45 can be served bythe LAN 40.

FIG. 42 is a block diagram showing the second modification of the hubapparatus shown in FIG. 40.

The hub apparatus according to the second modification is constructed bya power supply unit 11, current monitor 12, ringer output unit 13,hybrid unit 21, CODEC 22, PB receiver 23, tone generator 24,communication memory 31, FIFO_A 34, SIO_A 33, LAN interface 41, SIO_B42, FIFO_B 45, and CPU 50.

The same reference numerals in FIG. 42 denote the same parts as those inFIG. 40, and a detailed description thereof will be omitted.

The second modification is characterized in that the FIFO_A 34 andFIFO_B 45 are provided respectively in place of the DMAC_A 32 and DMAC_B43, and the communication memory 31 and CPU 50 replace each other. Notethat the FIFO_A 34 and FIFO_B 45 as new building elements have the samefunction as that of the DMAC_A 32 and DMAC_B 43. That is, the FIFO_A 34transfers encoded data between the CPU and SIO_A 33, and the FIFO_B 45transfers packetized data between the communication memory 31 and SIO_B42.

The operation of the hub apparatus with the aforementioned arrangementwill be explained below.

Formation of a voice channel upon receiving a voice communicationrequest from the LAN 40 will be explained first.

Upon receiving a communication request packet of an originatingapparatus from the LAN 40, the LAN interface 41 transmits the packet tothe SIO_B 42 as serial data. The SIO_B 42 converts the received serialdata into parallel data. The parallel data converted by the SIO_B 42 issequentially stored in the FIFO_B 45. The CPU 50 sequentially reads outthe parallel data stored in the FIFO_B 45, and stores the readout datain the communication memory 31.

The CPU 50 analyzes the packet data stored in the communication memory31. If the CPU 50 determines as a result of analysis that the receivedpacket is a communication request to the terminal 10 a, it checks thestatus of the terminal 10 a. If the terminal 10 a is idle, the CPU 50controls the ringer output unit 13 to output a ringer signal to theterminal 10 a so as to receive the call.

If the user of the terminal 10 a answers the call and a DC loop isformed, the current monitor 12 detects the DC current supplied from thepower supply unit 11, and informs the CPU 50 of it. Upon detecting theresponse, the CPU 50 informs the originating apparatus of that messageusing a response packet, and enables the CODEC 22 to form acommunication channel between the originating apparatus and terminal 10a.

Note that the response packet is transmitted to the originatingapparatus as follows. The response packet generated by the CPU 50 isstored in the FIFO_B 45. The SIO B 42 reads out this response packetfrom the FIFO_B 45 as parallel data, and converts the parallel data intoserial data. Then, the SIO_B 42 transmits the serial data to the LANinterface 41. The LAN interface 41 packetizes the serial data inaccordance with the protocol of the LAN 40, and transmits the packet tothe originating apparatus.

A communication method (by means of, e.g., voice) when the voice channelhas been formed in this way is as follows.

When an audio packet obtained by packetizing encoded audio data arrivesfrom the originating apparatus via the LAN interface 41, SIO_B 42, andFIFO_B 45 after a voice channel is formed, the CPU 50 temporarily storesaudio data (parallel data) in the communication memory 31 to separatethe data, and then stores audio data alone in the FIFO_A 34. Theparallel audio data stored in the FIFO_A 34 is sequentially read out bythe SIO_A 33. The SIO_A 33 converts the parallel audio data into serialaudio data, and outputs the serial audio data to the CODEC 22. The audiodata is decoded by the CODEC 22, is converted from four-wire data intotwo-wire data by the hybrid unit 21, and is then output as an analogaudio signal to the terminal 10 a.

An analog audio signal output from the terminal 10 a is converted fromtwo-wire data into four-wire data by the hybrid unit 21, and is thenoutput from the CODEC 22 as encoded serial data to the SIO_A 33. TheSIO_A 33 converts the serial audio data into parallel audio data, andsequentially stores the converted data in the FIFO_A 34. The audio datafrom the terminal 10 a stored in the FIFO_A 34 is transferred to thecommunication memory 31 by the CPU 50, is packetized by the CPU 50, andis then stored in the FIFO_B 45. The audio packet stored in the FIFO_B45 is read out as parallel data by the SIO_B 42, and is converted intoserial data. The serial data is transmitted to the LAN interface 41. TheLAN interface 41 packetizes the data in accordance with the protocol ofthe LAN 40, and transmits the packet to the originating apparatus.

A method of forming a communication channel upon receiving a calloriginating request from the terminal 10 a is as follows.

When the user of the terminal 10 a goes off-hook to form a DC loop, thecurrent monitor 12 detects the DC current supplied from the power supplyunit 11, and informs the CPU 50 of it. Upon detecting off-hook of theterminal 10 a, the CPU 50 controls the terminal 10 a to output a dialtone. When the terminal 10 a outputs a selection signal after itconfirms the dial tone, the PB receiver 23 decodes the selection signaland supplies it to the CPU 50. The CPU 50 specifies the terminatingapparatus on the basis of the number of the selection signal, generatesa communication request packet, and transmits the communication requestpacket to the LAN 40 via the FIFO_B 45, SIO_B 42, and LAN interface 41,in the same procedure as that for transmitting the response packet tothe originating apparatus, thus supplying the request packet to theterminating apparatus. Upon receiving a response packet from theterminating apparatus, the CPU 50 enables the CODEC 22 to form acommunication channel between the terminal 10 a and terminatingapparatus.

An example of the ISDN router apparatus will be explained in detailbelow.

FIG. 43 is a block diagram showing an embodiment of an ISDN routerapparatus according to the present invention. The ISDN router apparatusaccording to one embodiment of the present invention is constructed byan ISDN interface 14, CODEC 22, PB receiver 23, communication memory 31,DMAC_A 32, SIO_A 33, LAN interface 41, SIO_B 42, DMAC_B 43, and CPU 50.

The same reference numerals in FIG. 43 denote the same parts as those inFIG. 40, and a detailed description thereof will be omitted.

The ISDN router apparatus is different from the hub apparatus shown inFIG. 40 in that it does not require any functions (for example, thepower supply unit 11, current monitor 12, and the like in FIG. 40)inherent to the terminal 10 a shown in FIG. 40, and comprises the ISDNinterface 14 in place of such functions. The ISDN interface 14communicates with an ISDN network lOb and this apparatus.

The operation of the ISDN router apparatus with the aforementionedarrangement will be explained below.

Formation of a communication channel upon receiving a call terminatingrequest from a LAN 40 will be explained below.

Upon receiving a communication request packet of an originatingapparatus from the LAN 40, the LAN interface 41 transmits the packet tothe SIO_B 42 as serial data. The SIO_B 42 converts the received serialdata into parallel data. The parallel data converted by the SIO_B 42 istransferred to the communication memory 31 by the DMAC_B 43.

Upon completion of transfer to the communication memory 31, the CPU 50analyzes the packet data stored in the communication memory 31. If theCPU 50 determines as a result of analysis that the packet is acommunication request to the ISDN network lob, it checks the status ofthe network. If the network is idle, the CPU 50 starts communicationprocessing via the ISDN interface 14.

Upon detecting a response from the ISDN network lob, the CPU 50transmits a response packet to the originating apparatus to form acommunication channel between the originating apparatus and ISDN network10 b.

Note that the response packet is transmitted to the originatingapparatus as follows. The response packet generated by the CPU 50 isstored in the communication memory 31. The DMAC_B 43 reads out thisresponse packet from the communication memory 31 as parallel data, andtransfers the parallel data to the SIO_B 42. The SIO_B 42 converts theparallel data into serial data, and transmits the serial data to the LANinterface 41. The LAN interface 41 packetizes the serial data inaccordance with the protocol of the LAN 40, and transmits the packet tothe originating apparatus.

A communication method after the voice channel is formed in this way isas follows.

When an audio packet obtained by packetizing encoded audio data arrivesat the communication memory 31 from the originating apparatus via theLAN interface 41, SIO_B 42, and DMAC_B 43 after a voice channel isformed, the CPU 50 stores audio data (parallel data) alone in anotherarea of the communication memory 31. The DMAC_A 32 reads out theparallel audio data from the communication memory 31, and transfers thereadout data to the SIO_A 33. The SIO_A 33 converts the parallel audiodata into serial audio data and outputs the serial audio data to theISDN interface 14. The ISDN interface 14 sends the audio data to theISDN network 10 b via a Bch.

Audio data on the Bch received from the ISDN network 10 b is output fromthe ISDN interface 14 to the SIO_A 33 and CODEC 22. The SIO_A 33converts serial audio data into parallel audio data, which istransferred to the communication memory 31 by the DMAC_A 32. The audiodata from the ISDN network 10 b stored in the communication memory 31 ispacketized by the CPU 50, and is stored in another area of thecommunication memory 31. The DMAC_B 43 reads out the audio packet fromthe communication memory 31 as parallel data, and transfers the paralleldata to the SIO_B 42. The SIO_B 42 converts the parallel data intoserial data, and transmits the serial data to the LAN interface 41. TheLAN interface 41 packetizes the serial data in accordance with theprotocol of the LAN 40, and transmits the packet to the originatingapparatus.

The CODEC 22 decodes the audio data and transmits the decoded audio datato the PB receiver 23. Upon receiving a PB signal in the audio data, thePB receiver 23 decodes the PB signal, and supplies it to the CPU 50.

A method of forming a communication channel upon receiving a call fromthe ISDN network 10 b is as follows.

Upon detecting a communication request from the ISDN network 10 b, theCPU 50 specifies the terminating apparatus from the terminating number.Then, the CPU 50 generates a communication request packet, and transmitsthe packet to the LAN 40 via the communication memory 31, DMAC_B 43,SIO_B 42, and LAN interface 41 in the same procedure as that fortransmitting the response packet to the originating apparatus, thussupplying the packet to the terminating apparatus. Upon receiving aresponse packet from the terminating apparatus, the CPU 50 performscommunication processing via the ISDN interface 14 to form acommunication channel, and enables the CODEC 22 to receive a PB signalon the Bch from the ISDN network 10 b.

An example of a public network router apparatus will be described indetail below.

FIG. 44 is a block diagram showing an embodiment of a public networkrouter apparatus according to the present invention. The public networkrouter apparatus according to one embodiment of the present invention isconstructed by a ringer detector 15, polarity monitor 16, DC loopgenerator 17, hybrid unit 21, CODEC 22, PB receiver 23, tone detector25, PB signal generator 26, communication memory 31, DMAC_A 32, SIO_A33, LAN interface 41, SIO_B 42, DMAC_B 43, and CPU 50.

The same reference numerals in FIG. 44 denote the same parts as those inFIG. 40, and a detailed description thereof will be omitted.

The public network router is different from the hub apparatus shown inFIG. 40 in that the DC loop generator 17 replaces the power supply unit11, the polarity monitor 16 replaces the current monitor 12, the ringerdetector 15 replaces the ringer output unit 13, and the tone detector 25and PB generator 26 replace the tone generator 24, since a publicnetwork 10 c is connected in place of the terminal 10 a shown in FIG.40.

Referring to FIG. 44, the ringer detector 15 detects a ringer signalfrom the public network 10 c. The polarity monitor 16 monitors thepolarity of the network. The DC loop generator 17 opens/closes the DCcircuit. The tone detector 25 detects a call progress tone. The PBsignal generator 26 outputs a PB signal. Since other constructingelements are the same as those in FIG. 40, a description thereof will beomitted.

The operation of the public network router apparatus with theabove-mentioned arrangement will be explained below.

Formation of a voice channel upon reception of a voice communicationrequest from the LAN 40 will be explained first.

Upon receiving a communication request packet of an originatingapparatus from the LAN 40, the LAN interface 41 transmits the packet tothe SIO_B 42 as serial data. The SIO_B 42 converts the received serialdata into parallel data. The parallel data converted by the SIO_B 42 istransferred to the communication memory 31 by the DMAC_B 43.

Upon completion of transfer to the communication memory 31, the CPU 50analyzes the packet data stored in the communication memory 31. If theCPU 50 determines as a result of analysis that the received packet is acommunication request to the public network 10 c, it checks the statusof the network. If the network is idle, the DC loop generator 17 forms aDC loop to inform the public network 10 c of the communication request.

When the tone detector 25 detects a dial tone from the public network 10c and informs the CPU 50 of it, the CPU 50 outputs a selection signalfrom the PB generator 26 onto the public network 10 c. The polaritymonitor 16 monitors the polarity of the network. When the public network10 c responds by inverting the polarity, the polarity monitor 16 detectsit and informs the CPU 50 of the response. Upon detecting the response,the CPU 50 informs the originating apparatus of that message using aresponse packet, and enables the CODEC 22 to form a communicationchannel between the originating apparatus and public network 10 c.

Note that the response packet is transmitted to the originatingapparatus as follows. The response packet generated by the CPU 50 isstored in the communication memory 31. The DMAC_B 43 reads out thisresponse packet from the communication memory 31 as parallel data, andtransfers the parallel data to the SIO_B 42. The SIO_B 42 converts theparallel data into serial data, and transmits the serial data to the LANinterface 41. The LAN interface 41 packetizes the serial data inaccordance with the protocol of the LAN 40, and transmits the packet tothe originating apparatus.

A communication method (by means of, e.g., voice) when the voice channelhas been formed in this way is as follows.

When an audio packet obtained by packetizing encoded audio data arrivesat the communication memory 31 from the originating apparatus via theLAN interface 41, SIO_B 42, and DMAC_B 43 after a voice channel isformed, the CPU 50 stores audio data (parallel data) alone in anotherarea of the communication memory 31. The DMAC_A 32 reads out theparallel audio data from the communication memory 31, and transfers thatdata to the SIO_A 33. The SIO_A 33 converts the parallel audio data intoserial audio data, and outputs the serial audio data to the CODEC 22.The audio data is decoded by the CODEC 22, is converted from four-wiredata into two-wire data by the hybrid unit 21, and is then output as ananalog audio signal onto the public network 10 c.

An analog audio signal output from the terminal 10 a is converted fromtwo-wire data into four-wire data by the hybrid unit 21, and is theoutput from the CODEC 22 as encoded serial data to the SIO_A 33. TheSIO_A 33 converts the serial audio data into parallel audio data, andthe converted parallel data is transferred to the communication memory31 by the DMAC_A 32. The audio data from the public network 10 c storedin the communication memory 31 is packetized by the CPU 50, and isstored in another area of the communication memory 31. The DMAC_B 43reads out the audio packet from the communication memory 31 as paralleldata, and transfers the parallel data to the SIO_B 42. The SIO_B 42converts the parallel data into serial data, and transmits the serialdata to the LAN interface 41. The LAN interface 41 packetizes the serialdata in accordance with the protocol of the LAN 40, and transmits thepacket to the originating apparatus.

A method of forming a communication channel upon receiving a calloriginating request from the public network 10 c is as follows.

Upon detecting a ringer signal from the public network 10 c, the ringerdetector 15 informs the CPU 50 of it. The CPU 50 controls the DC loopgenerator 17 to form a DC loop and waits for a selection signal. Whenthe public network 10 c outputs a selection signal, the PB receiver 23decodes and supplies it to the CPU 50. The CPU 50 specifies theterminating apparatus on the basis of the number of the selectionsignal, controls the DC loop generator 17 to open a DC loop, generates acommunication request packet, and transmits the packet to the LAN 40 viathe communication memory 31, DMAC_B 43, SIO_B 42, and LAN interface 41in the same procedure as that for transmitting the response packet tothe originating apparatus, thus supplying the request packet to theterminating apparatus. Upon receiving a response packet from theterminating apparatus, the CPU 50 controls the DC loop generator 17 toform a DC loop again, and enables the CODEC 22 to form a communicationchannel between the public network 10 c and terminating apparatus. Thepublic network 10 c re-inverts the polarity to become ready tocommunicate.

An example of a radio hub apparatus will be explained in detail below.

FIG. 45 is a block diagram showing an embodiment of a radio hubapparatus according to the present invention. The radio hub apparatusaccording to one embodiment of the present invention is constructed by aradio unit 10 d, CODEC 22, PB receiver 23, tone generator 24,communication memory 31, DMAC_A 32, SIO_A 33, LAN interface 41, SIO_B42, DMAC_B 43, and CPU 50.

The same reference numerals in FIG. 45 denote the same parts as those inFIG. 40, and a detailed description thereof will be omitted.

The radio hub apparatus is different from the hub apparatus shown inFIG. 40 in that the radio unit 10 d replaces the hybrid unit 21 to theterminal 10 a in FIG. 40, and can communicate with a radio station 60via radio.

Note that the radio unit 10 d transmits/receives a radio wave to/fromthe radio station 60.

The operation of the radio hub apparatus with the above-mentionedarrangement will be explained below.

Formation of a voice channel upon reception of a call terminatingrequest from the LAN 40 will be explained first.

Upon receiving a communication request packet of an originatingapparatus from the LAN 40, the LAN interface 41 transmits the packet tothe SIO_B 42 as serial data. The SIO_B 42 converts the received serialdata into parallel data. The parallel data converted by the SIO_B 42 istransferred to the communication memory 31 by the DMAC_B 43.

Upon completion of transfer to the communication memory 31, the CPU 50analyzes the packet data stored in the communication memory 31. If theCPU. 50 determines as a result of analysis that the received packet is acommunication request to the radio station 60, it checks the status ofthe radio station 60. If the radio station 60 is idle, the CPU 50 startscommunication processing via the radio unit 10 d.

Upon detecting a response from the radio station, the CPU 50 informs theoriginating apparatus of that message using a response packet to form acommunication channel between the originating apparatus and radiostation 60.

Note that the response packet is transmitted to the originatingapparatus as follows. The response packet generated by the CPU 50 isstored in the communication memory 31. The DMAC_B 43 reads out thisresponse packet from the communication memory 31 as parallel data, andtransfers the parallel data to the SIO_B 42. The SIO_B 42 converts theparallel data into serial data, and transmits the serial data to the LANinterface 41. The LAN interface 41 packetizes the serial data inaccordance with the protocol of the LAN 40, and transmits the packet tothe originating apparatus.

A communication method used when the voice channel has been formed inthis way is as follows.

When an audio packet obtained by packetizing encoded audio data arrivesat the communication memory 31 from the originating apparatus via theLAN interface 41, SIO_B 42, and DMAC_B 43 after a voice channel isformed, the CPU 50 stores audio data (parallel data) alone in anotherarea of the communication memory 31. The DMAC_A 32 reads out theparallel audio data from the communication memory 31, and transfers thatdata to the SIO_A 33. The SIO_A 33 converts the parallel audio data intoserial audio data, and outputs the serial audio data to the radio unit10 d. The radio unit 10 d outputs the audio data to the radio station 60on a radio wave.

Audio data on a radio wave received from the radio station 60 is outputfrom the radio unit 10 d to the SIO_A 33 and CODEC 22. The SIO_A 33converts the serial audio data into parallel audio data, which istransferred to the communication memory 31 by the DMAC_A 32. The audiodata from the radio station 60 stored in the communication memory 31 ispacketized by the CPU 60, and is stored in another area of thecommunication memory 31. The DMAC_B 43 reads out the audio packet fromthe communication memory 31 as parallel data and transfers the readoutdata to the SIO_B 42. The SIO_B 42 converts the parallel data intoserial data and transmits the serial data to the LAN interface 41. TheLAN interface 41 packetizes the serial data in accordance with theprotocol of the LAN 40 and transmits the packet to the originatingapparatus.

The CODEC 22 decodes the audio data and transmits the decoded audio datato the PB receiver 23. Upon receiving a PB signal in the audio data, thePB receiver 23 decodes the PB signal, and supplies it to the CPU 50.

A method of forming a communication channel upon receiving a calloriginating request from the radio station is as follows.

Upon detecting a communication request from the radio station 60, theCPU 50 specifies the terminating apparatus from the terminating number.Subsequently, the CPU 50 generates a communication request packet, andtransmits the packet to the LAN 40 via the communication memory 31,DMAC_B 43, SIO_B 42, and LAN interface 41 in the same procedure as thatfor transmitting the response packet to the originating apparatus, thussupplying the request packet to the terminating apparatus. In addition,the CPU 50 controls the tone generator 24 to output a call progress toneto the radio station 60. Upon receiving a response packet from theterminating apparatus, the CPU 50 executes communication processing viathe radio unit 10 d to form a communication channel, and enables theCODEC 22 to receive a PB signal from the radio station 60.

As described above, according to the present invention, the dataconversion processes of the respective terminal apparatuses aredistributed to communication interface apparatuses corresponding to theterminal apparatuses as in the above-mentioned examples, and eachcommunication interface apparatus need only have a data conversionfunction between, e.g., one type of communication protocol on theterminal apparatus side and only one type of communication protocol onthe first communication network (the LAN in this embodiment) side, andneed not have all data conversion functions corresponding to a pluralityof types of communication protocols versus a plurality of types ofcommunication protocols.

Hence, according to the present invention, a plurality of kinds ofcommunications can be implemented by a common communicationinfrastructure (e.g., the LAN) without requiring any large-scaleequipment such as a PBX, gateway, and the like.

As described in detail above, in a multimedia information communicationsystem according to one embodiment of the present invention, a radiobase station, analog telephone hub apparatus, business telephone hubapparatus, and hub apparatus for a personal computer are connected ascommunication interface apparatuses for extension terminals to the LAN,and respectively serve extension terminals. Furthermore, an ISDN routerapparatus and PSTN router apparatus are connected as communicationinterface apparatuses for outside lines to the LAN, and these routerapparatuses connect the LAN to an ISDN and PSTN. Each communicationinterface for the extension performs protocol conversion and dataconversion between each extension terminal and LAN, and eachcommunication interface apparatus for the outside line performs protocolconversion and data conversion between the LAN and public network.

Therefore, according to the above-mentioned embodiment, both an audiosignal transmitted from an analog telephone and data transmitted from adata terminal such as a personal computer or the like are converted intoa single data format corresponding to the communication protocol of theLAN by the corresponding hub apparatuses, and the converted data arethen output onto the LAN. Data transferred on the LAN is converted intoa data format corresponding to the communication protocol of a givenextension terminal by a terminating hub apparatus, and is then sent tothe extension terminal. For this reason, a plurality of kinds ofcommunications can be implemented using a single infrastructure, i.e., acore (first) communication network (e.g., the LAN).

In addition, data conversion processes that pertain to the individualextension terminals are distributed to the corresponding hubapparatuses, and each hub apparatus need only have a data conversionfunction between only one type of communication protocol correspondingto its extension terminal, and only one type of communication protocolfor the LAN on the LAN 1 side but need not have data conversionfunctions of all the combinations corresponding to a plurality of typesof communication protocols versus a plurality of types of communicationprotocols. Hence, no large-scale communication equipment for integratedprocessing such as double PBXs, gateway, and the like is required, and asystem can be realized by preparing a plurality of hub apparatuseshaving simple functions, thus attaining a simple system arrangement anda great cost reduction.

Upon connecting a new extension terminal or changing connections, afteran arbitrary extension terminal is connected to the LAN 1 via a hubapparatus, a simple setup process need only be done without requiringany complicated setups. Consequently, a system which has highexpandability and allows easy maintenance- management can be provided.

The second embodiment of a multimedia information communication systemaccording to the present invention will be explained below. FIG. 46 is aschematic diagram showing the arrangement of a CTI (Computer TelephonyIntegration) system according to the second embodiment. Theaforementioned embodiment has exemplified the LAN using Ethernet asmeans for connecting the respective communication interface apparatuses.However, this embodiment will exemplify a case wherein the respectiveapparatuses are connected using an IEEE1394 interface, which is a kindof serial interface, and is beginning to be used as a home bus or thelike in recent years. However, in the second embodiment as well, therespective apparatuses may be connected using a LAN (may use eitherEthernet or other networks), and another interface such as a USB(Universal Serial Bus) or the like may be used in place of IEEE1394.

Note that as a communication protocol for packets on a network in thisembodiment, an RTP (Real Time Transparent Protocol) that can transferaudio and video data in real time is used to cope with an audio meeting,video meeting, and the like.

A communication terminal apparatus 104 is connected to a network 102 viaan interface apparatus 106. Note that the IEEE1394 interface connectstwo apparatuses in daisy-chain to form a network. The communicationterminal apparatus includes a standard telephone, multi-functionaldigital telephone, video telephone, facsimile apparatus, master unit ofa PHS system, terminal apparatus of a video meeting system, and thelike.

A communication network 108 is connected to the network 102 via aninterface apparatus 110. The communication network includes a publicnetwork (PSTN), ISDN network, frame relay network, and the like. Theinterface apparatuses 110 and 106 have basically the same arrangement,which is shown in detail in FIG. 47.

A personal computer 112 having a telephone function is connected to thenetwork 102 as a communication terminal apparatus. The personal computerhas a microphone 132, loudspeaker 134, and television camera 135 inaddition to a CPU 120, ROM 122, RAM 124, keyboard 126, display 128, andnetwork interface 130 as in a normal one. The CPU 120 converts an audiosignal and video signal from the network interface 130 into those forthe loudspeaker 134 and display 126, and outputs the converted signals.Also, the CPU 120 converts signals from the microphone 132 and camera135 into those for the network interface 130, and outputs the convertedsignals.

CTI servers 114 and 116 for controlling communications betweencommunication terminal apparatuses are connected to the network 102.Note that one of the two servers is a backup server, and the two serversneed not operate at the same time. For this reason, in order to doublethe control function, two physically different servers need not alwaysbe provided, and a single server may functionally double the control.Furthermore, the control function may be distributed to the respectiveinterface apparatuses without being concentrated on a single server.Even when the CTI server is provided, each interface apparatus may havea simple communication control function. The CTI servers 114 and 116have the same arrangement, i.e., have a CPU 138, ROM 140, RAM 136,network interface 142, and external storage interface 144. The externalstorage interface 144 serves a floppy disk FD, hard disk HD, and thelike.

FIG. 47 is a block diagram showing the arrangement of the interfaceapparatus 110 connected to a communication network, especially, the ISDNnetwork. The interface apparatus 110 converts between the communicationprotocol of the communication network 108 and that of the network 102.The ISDN network is connected to a protocol terminating equipment 202.The terminating equipment 202 separates signals coming from the ISDNnetwork into digital and analog signals, and respectively supplies thesesignals to a digital signal processor 208 and analog signal processor210. The digital signal processor 208 and analog signal processor 210serve as selection switches for respectively analyzing the digital andanalog signals from the protocol terminating equipment 202 and supplyingthe analyzed signals to predetermined processing circuits at theiroutput side.

A G4 FAX processor 214, H.320 processor 218, PPP (point-to-pointprotocol) processor 220, and the like are connected to the digitalsignal processor 208. The output from the G4 FAX processor 214 issupplied to an internet FAX processor via a G4FAX/internet FAX protocolconverter 222. The output from the H.320 processor 218 is supplied to anH323 processor 232 via an H.320/H.323 protocol converter 230. The outputfrom the PPP processor 220 is supplied to an IP processor 236 via aPPP/IP (internet protocol) converter 234.

A modem 212 and audio processor 242 are connected to the analog signalprocessor 210. The PPP processor 220, an H.324 processor 238, a G3 FAXprocessor 240, and the like are connected to the modem 212. The outputfrom the H.324 processor 238 is supplied to an H.323 processor 246 viaan H.324/H.323 protocol converter 244. The output from the G3 FAXprocessor 240 is supplied to an internet FAX processor 250 via a G3FAX/internet FAX protocol converter 248. The output from the audioprocessor 242 is supplied to an H.323 processor 254 via an audio/H.323protocol converter 254.

The outputs from the internet FAX protocol unit 224, H.323 processor232, IP processor 236, H.323 processor 246, internet FAX processor 250,and H.323 processor 254 are connected to the network 102 via a protocolterminating equipment 256.

That is, the interface apparatus 110 has a function of terminatingprotocols such as G3 FAX, H.324, and PPP connection by means of audioand analog modem data, and PPP connection, H.320 TV meeting, G4FAX, andthe like by means of digital communications, as the communicationprocedures on the ISDN network, a function of terminating H.323,internet FAX protocol, IP connection, and the like as the correspondingprotocols on the network, and a protocol conversion function ofconverting these protocols to each other. The ISDN 108 and network 102are connected to each other by switching switches in the terminatingequipments 202 and 256 in correspondence with a communication protocolat the beginning of or during a communication to select a requiredprotocol conversion section. A CPU 258 controls the terminatingequipments 202 and 256 to select a connection protocol. As describedabove, the CPU 258 may have a portion of the communication connectioncontrol function of the CTI servers 114 and 116. Note that the protocolconverters may be implemented by software by the CPU 258 instead ofhardware.

Note that the interface apparatus 110 need not always include all thecomponents of the arrangement shown in FIG. 47, and need only haveconverters corresponding to the protocols of the communication network108. Similarly, the interface apparatus 106 connected to thecommunication terminal apparatus 104 need not always include all thecomponents of the arrangement shown in FIG. 47, and need only haveconverters corresponding to the protocols of the communication terminalapparatus 104.

FIG. 48 is a chart for explaining the basic connection procedure in theembodiment shown in FIG. 46.

When one (originating apparatus 262) of the communication terminalapparatus 104, personal computer 112, and a communication terminalapparatus connected to the communication network 108 begins tocommunicate with another apparatus (terminating apparatus), it suppliesa caller number and login information as originating side information, aterminating side number, name, and service as terminating sideinformation, and a communication condition such as audio, video, data,or the like to one of communication connection controllers 264 (stepS1). The communication connection controller 264 may be any of the CPU138 in the CTI server 114 or 116, the CPU 258 in each interfaceapparatus, and the CPU 120 in the personal computer 112.

The communication connection controller 264 extracts detailedinformation that pertains to the caller (the language, address, age,past communication record, operator record, transaction log, and thelike of the caller) by referring to an originating side database 266(step S2). The database 266 is stored in the hard disk HD of the CTIserver 114.

The communication connection controller 264 informs, based on thisinformation, apparatuses 270 and 272 that belong to the same group asthe caller (a group used when a PBX classifies terminals into groups tomanage them) that the originating apparatus 262 has started acommunication (step S3).

Subsequently, data such as a communication start time, networkcondition, and the like, which are not directly associated withoriginating and terminating side data are extracted by referring to anetwork database 268 (step S4).

When the communication connection controller 264 on the caller sidecannot refer to the database of terminating side information requestedfrom the caller side, information required for connection acquired fromthe databases 266 and 268 is transferred to a communication connectioncontroller 276 having route information of the terminating terminal soas to access a communication connection controller 276 that can refer tothe terminating side information (step S5-1). A communication connectioncontroller 274 selects a communication connection controller 276 thatcan refer to information of the terminating side terminal, and transfersinformation received from the communication connection controller 264and information required upon reference by the communication connectioncontroller 274 to the communication connection controller 276 (stepS5-2).

The communication connection controller 276 extracts information thatpertains to the callee (the language, address, age, past communicationrecord, operator record, transaction log, and the like of the callee) byreferring to a terminating side database 278 on the basis of thereceived terminating side information (step S6). Similarly, thecontroller 276 extracts data such as a communication start time, networkcondition, and the like, which are not directly associated with theoriginating and terminating side data by referring to the networkdatabase 268 (step S7).

The communication connection controller 276 determines one or aplurality of terminating side terminals that are actually to receive thecall, with reference to register information and operating informationof operators of the terminal apparatuses 262, 270, and 272, which areassociated with the groups on the caller side, and informs terminatingside apparatuses 280, 282, and 284 of the presence of an incoming call(step S8). The terminating side terminal informs the originating sideterminal 262 of the beginning of ringing via the communicationconnection controllers 276, 274, and 264 (steps S9-1, S9-2, S9-3, andS9-4).

After that, a communication between the originating side apparatus 262and terminating side apparatus 280 is realized (step S10). As describedabove, a series of these communication connection procedures may beimplemented by the CPU 138 alone on the single CTI server 114, but maybe easily modified so that these procedures are respectively containedin individual communication terminal apparatuses.

The basic communication connection procedures between two parties havebeen described. According to this embodiment, audio data is alsoprocessed (transferred on the network) as a packet, and data and audioprocesses can be unified. Since no line exchange is required unlike in aconventional telephone exchange, communication controllers can bedistributed, thus allowing easily maintenance. In addition, a terminalcan be set by the user since it need only be connected to the network102 via the interface apparatus 106. Furthermore, a new terminal can besimilarly connected, thus assuring high expandability.

Since a computer and telephone can be completely integrated,voice/e-mail unification (unified message), a telephone directoryoriginating function (directory service), a voice mail function, a FAXmail function, a voice recognition function, and an e-mailtext-to-speech function can be implemented. Furthermore, various kindsof services provided by the conventional ISDN are also available: forexample, a call center function, a caller ID informing function, and anautomatic voice answering function.

Some examples will be explained below.

FIG. 49 shows a method of implementing a voice mail when the user at theterminating side terminal does not answer. In this case, the CTI server114 includes a voice mail device 308, an audio storage unit 310, and aspeech/text converter 312, and an independent mail server 314 is added.

A case will be examined below wherein a call originated from a telephoneconnected to the ISDN network is received by an originating sideinterface apparatus 302 (step S20), and is then received by aterminating side apparatus 304 (step S22).

If the terminating side apparatus 304 does not answer the call for apredetermined period of time or all terminating terminals are busy andcannot answer, a communication connection controller 306 re-connects bychanging the terminating apparatus to the voice mail device 308 in theCTI server 114 in accordance with information prestored in a terminatingside information database (step S24). The voice mail device 308automatically answers and sends back a voice message “We are not hereright now. Please leave your message.”, and if the user at the telephoneconnected to the ISDN network leaves a message in the same manner as avoice mail (step S26), the voice mail device 308 saves that audio datain the audio storage unit 310 as an audio file (step S28).

Next, the audio file in the audio storage unit 310 is read by the voicemail device 308 (step S30), and is converted into an attached file of ane-mail by the speech/text converter 312 (step S32). Then, the e-mail issent to the mail server 314 as the one addressed to the terminating sideapparatus 304 that could not answer (step S34).

In this manner, an e-mail by means of text and a voice mail by means ofvoice can be easily unified using the e-mail mechanism on the network.

FIG. 50 shows a method of implementing an e-mail text-to-speechfunction. In this case, the CTI server 114 comprises a mailtext-to-speech application 408, and text/speech converter 410, and anindependent mail server 412 is added.

A case will be examined below wherein a call originated from a telephoneconnected to the ISDN network is received by an originating sideinterface apparatus 402 (step S40), and is then received by aterminating side apparatus 404 (step S42).

The terminating side apparatus 404 is directly terminated by the e-mailtext-to-speech application 408 in the CTI server 114. In such case, if aperson calls using a telephone, the caller ID of which indicates his orher home, or the like, and must be the person himself or herself, perauthentication is done by, e.g., simply collating a password (ID). If aperson calls using a public telephone, after an ID is input, personalauthentication data is accessed on the basis of caller informationobtained from a communication connection controller 406 upon connectionto require input of an arbitrary combination of information that can beused for personal authentication, so as to check the caller'sauthenticity. In this manner, the security level can be changed in unitsof originating side terminals and access means.

After the ID has been confirmed, the mail server 412 is accessed usingthis ID to acquire an e-mail (step S46). This text information isconverted into an audio file using the text/speech converter 410 (stepS48), and the converted file can be read back as speech to the caller(steps S50 and S52).

In this way, a text-to-speech system can be easily built. Note that theuser can give priority depending on the mail sender, title, contents,and the like. Also, flexible setups (e.g., the mail contents are readback after its title is confirmed) can be made by this mailtext-to-speech application.

A case will be explained wherein an electronic meeting is held. Since aplurality of persons join the electronic meeting, voices of a pluralityof attendants must be synthesized. This synthesis is done by the CTIserver 114. For example, when three persons A, B, and C are in meeting,B's and C's audio packets are synthesized and supplied to A; A's and C'saudio packets are synthesized and supplied to B; and A's and B's audiopackets are synthesized and supplied to C. Note that if the number ofattendants of a meeting is n, nC2×2 voice synthesis functions need onlybe prepared.

Note that the communication connection controller may change theterminating side interface apparatus or the communication connectioncontroller itself in correspondence with a request from the originatingside interface apparatus or terminating side interface apparatus, orchanges in state of the network. When audio data of a voicecommunication is transferred to another apparatus, the communicationconnection controller may change the transfer destination (communicationconnection mode) in correspondence with a request from the originatingside interface apparatus or terminating side interface apparatus, orchanges in state of the network. Furthermore, the communicationconnection controller may have a call center function of callingoriginating and terminating side interface apparatuses in turn toconnect them to each other and to make them communicate with each other(so-called third party call).

As described above, according to the present invention, when an audiocommunication terminal represented by a telephone is connected to acomputer network via an interface apparatus that converts between thecommunication protocol of the network and the communication protocolunique to the terminal, a multimedia information communication systemwhich allows the audio communication terminal to serve as one terminalof the computer network, and can obviate the need for a time switch forline exchange by exchanging audio data as packets on the network, can berealized.

Industrial Applicability

To restate, according to the present invention, both an audio signaltransmitted from, e.g., an audio communication terminal and datatransmitted from a data terminal such as a personal computer or the likeare converted into an identical data format corresponding to thecommunication protocol of a first communication network by acommunication interface apparatus, and the converted data are then sentonto the first communication network. The data transferred on the firstcommunication network is converted into a data format corresponding tothe communication protocol of a voice communication terminal or dataterminal by a terminating communication interface apparatus, and is thensent to a terminal apparatus. For this reason, a plurality of kinds ofcommunications can be implemented using a single infrastructure, i.e.,the first communication network.

In addition, the data conversion processes of the respective terminalapparatuses are distributed to communication interface apparatusescorresponding to the terminal apparatuses, and each communicationinterface apparatus need only have a data conversion function between,e.g., one type of communication protocol on the terminal apparatus sideand only one type of communication protocol on the first communicationnetwork side, and need not have all data conversion functionscorresponding to a plurality of types of communication protocols versusa plurality of types of communication protocols. For this reason, nolarge-scale communication equipment for integrated processing such asdouble PBXs, gateway, and the like is required, and a system can beimplemented by preparing a plurality of communication interfaceapparatuses having simple functions, thus attaining a simple systemarrangement and a great cost reduction.

Upon connecting a new terminal apparatus or changing connections, afteran arbitrary terminal apparatus is connected to the first communicationnetwork via a communication interface apparatus, a simple setup processneed only be done without requiring any complicated setups. Hence, asystem which has high expandability and allows easy maintenancemanagement can be provided.

Therefore, according to the present invention, a low-cost,high-reliability multimedia information communication system which canrealize a plurality of kinds of communications by a common communicationinfrastructure without equipping any large-scale equipment such as aPBX, gateway, and the like, and can make the system arrangement simpleand maintenance management easy can be provided.

What is claimed is:
 1. A multimedia information communication systemcomprising: first and second communication terminal apparatuses forexchanging information data using a common first communication protocolor first and second communication protocols which are different fromeach other; a first communication network for transmitting informationdata in accordance with a third communication protocol different fromthe first and second communication protocols; first and secondcommunication interface apparatuses for respectively connecting saidfirst and second communication terminal apparatuses to said firstcommunication network; and a third communication interface apparatus forconnecting said first communication network to a second communicationnetwork which transmits information data in accordance with a fourthcommunication protocol which is different from at least the thirdcommunication protocol, wherein said first communication interfaceapparatus comprises first conversion means for converting informationdata in accordance with the first and third communication protocolsbetween said first communication terminal apparatus and said firstcommunication network, said second communication interface apparatuscomprises second conversion means for converting information data inaccordance with the second and third communication protocols betweensaid second communication terminal apparatus and said firstcommunication network, and said third communication interface apparatuscomprises third conversion means for converting information data incorrespondence with a difference between the third and fourthcommunication protocols between said second and first communicationnetworks, and wherein said third communication interface apparatuscomprises first communication interface means for communicating withsaid first communication network, codec means for decoding informationobtained from said first communication network or information obtainedfrom said second communication network by said communication interfacemeans, or encoding information to be output to said first or secondcommunication network, a PB receiver for decoding a PB signal from saidsecond communication network, and second communication interface meansfor communicating with said second communication network.
 2. Amultimedia information communication system according to claim 1,wherein said third communication interface apparatus comprises firstcommunication interface means for communicating with said firstcommunication network, codec means for decoding information obtainedfrom said first communication network by said communication interfacemeans, or encoding information to be output to said first communicationnetwork, and second communication interface means for communication withsaid second communication network.
 3. A multimedia informationcommunication system according to claim 1, wherein at least one of saidfirst, second, and third conversion means comprises a plurality of dataconversion means provided in correspondence with types of informationdata, data type determination means for determining a type of inputinformation data, and selection means for selectively enabling saidplurality of data conversion means in accordance with a determinationresult of said data type determination means to convert the informationdata.
 4. A multimedia information communication system comprising: firstand second communication terminal apparatuses for exchanging informationdata using a common first communication protocol or first and secondcommunication protocols which are different from each other; a firstcommunication network for transmitting information data in accordancewith a third communication protocol different from the first and secondcommunication protocols; first and second communication interfaceapparatuses for respectively connecting said first and secondcommunication terminal apparatuses to said first communication network;and a third communication interface apparatus for connecting said firstcommunication network to a second communication network for transmittinginformation data in accordance with a fourth communication protocoldifferent from the third communication protocol, wherein each of saidfirst and second interface apparatuses comprises; inquiry means for,when a communication terminal apparatus served by the own apparatusgenerates a call originating request addressed to a communicationterminal apparatus served by another communication interface apparatus,multi-address transmitting an inquiry signal containing firstidentification information assigned to the terminating communicationterminal apparatus to all communication interface apparatuses connectedto said first communication network; determination means for, when aninquiry signal reaches via said first communication network, determiningif a communication terminal apparatus corresponding to the firstidentification information contained in the inquiry signal is served bythe own apparatus; response signal transmission means for, when saiddetermination means determines that the communication terminal apparatusof interest is served by the own apparatus, sending back a responsesignal containing second identification information assigned to the ownapparatus on said first communication network to an originatingcommunication interface apparatus via said first communication network;and first communication link formation means for, when the responsesignal is sent back, performing processing for forming a communicationlink between the own apparatus and the terminating communicationinterface apparatus on said first communication network on the basis ofthe second identification information contained in the response signal.5. A multimedia information communication system according to claim 4,wherein each of said first and second communication interfaceapparatuses comprises: identification information storage means for,when the response signal is sent back, storing the second identificationinformation contained in the response signal together with firstidentification information corresponding to a partner communicationterminal apparatus in correspondence with each other; first acquisitionmeans for, when a communication terminal apparatus served by the ownapparatus generates a call originating request addressed to acommunication terminal apparatus served by another communicationinterface apparatus, acquiring second identification informationassigned to a communication interface apparatus that serves theterminating communication terminal apparatus from said identificationinformation storage means; and second communication link formation meansfor, when said first acquisition means acquires the secondidentification information assigned to the terminating communicationinterface apparatus, performing processing for forming a communicationlink that connects between the own communication interface apparatus andterminating communication interface apparatus on said firstcommunication network on the basis of the second identificationinformation.
 6. A multimedia information communication system accordingto claim 5, wherein said identification information storage means storesfirst identification information and second identification informationacquired by the own communication interface apparatus by the inquiry,and first identification information and second identificationinformation acquired by another communication interface apparatus by theinquiry.
 7. A multimedia information communication system according toclaim 4, further comprising a server apparatus, which is connected tosaid first communication network, and has a function of intensivelystoring the first identification information and second identificationinformation acquired by said first and second communication interfaceapparatuses by the inquiry, and wherein each of said first and secondcommunication interface apparatuses comprises: second acquisition meansfor, when a communication terminal apparatus served by the own apparatusgenerates a call originating request addressed to a communicationterminal apparatus served by another communication interface apparatus,acquiring second identification information assigned to a communicationinterface apparatus that serves the terminating communication terminalapparatus from said server apparatus; and third communication linkformation means for, when said second acquisition means acquires thesecond identification information assigned to the terminatingcommunication interface apparatus, performing processing for forming acommunication link that connects between the own communication interfaceapparatus and terminating communication interface apparatus on saidfirst communication network on the basis of the second identificationinformation.
 8. A multimedia information communication system accordingto claim 4, wherein said third communication interface apparatuscomprises identification information storage means for intensivelystoring the first identification information and second identificationinformation acquired by said first and second communication interfaceapparatuses by the inquiry, and each of said first and secondcommunication interface apparatuses comprises: third acquisition meansfor, when a communication terminal apparatus served by the own apparatusgenerates a call originating request addressed to a communicationterminal apparatus served by another communication interface apparatus,acquiring second identification information assigned to a communicationinterface apparatus that serves the terminating communication terminalapparatus from said identification information storage means of saidthird communication interface apparatus; and fourth communication linkformation means for, when said third acquisition means acquires thesecond identification information assigned to the terminatingcommunication interface apparatus, performing processing for forming acommunication link that connects between the own communication interfaceapparatus and terminating communication interface apparatus on saidfirst communication network on the basis of the second identificationinformation.
 9. A multimedia information communication system accordingto claim 4, further comprising a server apparatus, which is connected tosaid first communication network, and has a function of intensivelystoring the first identification information and second identificationinformation acquired by said first and second communication interfaceapparatuses by the inquiry, and wherein each of said first and secondcommunication interface apparatuses comprises: identificationinformation storage means for, when a response signal to the inquirysignal is sent back, storing second identification information containedin the response signal together with first identification informationassigned to a terminating communication terminal apparatus incorrespondence with each other; first search means for, when acommunication terminal apparatus served by the own apparatus generates acall originating request addressed to a communication terminal apparatusserved by another communication interface apparatus, searching saididentification information storage means of the own apparatus for secondidentification information assigned to a communication interfaceapparatus that serves the terminating communication terminal apparatus;second search means for, when said first search means cannot find thesecond identification information by the search, searching said serverapparatus for the second identification information; third search meansfor, when said second search means cannot find the second identificationinformation by the search, multi-address transmitting an inquiry signalcontaining first identification information corresponding to theterminating communication terminal apparatus to all communicationinterface apparatuses connected to said first communication network, andacquiring second identification information assigned to thecommunication interface apparatus that serves the terminatingcommunication terminal apparatus, on the basis of a response signal tothe inquiry signal; and fifth communication link formation means for,when one of said first, second, and third search means acquires thesecond identification information assigned to the communicationinterface apparatus that serves the terminating communication terminalapparatus, performing processing for forming a communication link forconnecting between the own communication interface apparatus andterminating communication interface apparatus on said firstcommunication network on the basis of the second identificationinformation.
 10. A multimedia information communication systemcomprising first and second communication terminal apparatuses forexchanging information data using a common first communication protocolor first and second communication protocols which are different fromeach other; a first communication network for transmitting informationdata in accordance with a third communication protocol different fromthe first and second communication protocols; first and secondcommunication interface apparatuses for respectively connecting saidfirst and second communication terminal apparatuses to said firstcommunication network; and a third communication interface apparatus forconnecting said first communication network to a second communicationnetwork for transmitting information data in accordance with a fourthcommunication protocol different from the third communication protocol,wherein each of said first and second interface apparatuses comprises:inquiry signal transmission means for, when a communication terminalapparatus served by the own apparatus generates a call originatingrequest addressed to a communication terminal apparatus served byanother communication interface apparatus, transmitting an inquirysignal containing identification information corresponding to theterminating communication terminal apparatus onto said firstcommunication network, and said third communication interface apparatuscomprises: terminating apparatus determination means for receiving theinquiry signal, and determining based on the identification informationcontained in the inquiry signal if the terminating communicationterminal apparatus is a communication terminal apparatus which is servedby said first or second communication interface apparatus inside saidsystem, or a communication terminal apparatus which is connected to saidsecond communication network outside said system; and communication linkformation means for selectively performing first control for forming acommunication link for connecting between said first or secondcommunication interface apparatus that serves an originatingcommunication terminal apparatus and said first or second communicationinterface apparatus that serves the terminating communication terminalapparatus, and second control for forming a communication link betweensaid first or second communication interface apparatus that serves theoriginating communication terminal apparatus and the terminatingcommunication terminal apparatus connected to said second communicationnetwork, in accordance with a determination result of said terminatingapparatus determination means.
 11. A multimedia informationcommunication system comprising: first and second communication terminalapparatuses for exchanging information data using a common firstcommunication protocol or first and second communication protocols whichare different from each other; a first communication network fortransmitting information data in accordance with a third communicationprotocol different from the first and second communication protocols;first and second communication interface apparatuses for respectivelyconnecting said first and second communication terminal apparatuses tosaid first communication network; a third communication interfaceapparatus for connecting said first communication network to a secondcommunication network for transmitting information data in accordancewith a fourth communication protocol different from the thirdcommunication protocol; and a server apparatus connected to said firstcommunication network, wherein each of said first and secondcommunication interface apparatuses comprises: inquiry signaltransmission means for, when a communication terminal apparatus servedby the own apparatus generates a call originating request addressed to acommunication terminal apparatus served by another communicationinterface apparatus, transmitting an inquiry signal containingidentification information corresponding to the terminatingcommunication terminal apparatus onto said first communication network,and said server apparatus comprises: terminating apparatus determinationmeans for receiving the inquiry signal, and determining based on theidentification information contained in the inquiry signal if theterminating communication terminal apparatus is a communication terminalapparatus which is served by said first or second communicationinterface apparatus inside said system, or a communication terminalapparatus which is connected to said second communication networkoutside said system; and communication link formation means forselectively performing first control for forming a communication linkfor connecting between said first or second communication interfaceapparatus that serves an originating communication terminal apparatusand said first or second communication interface apparatus that servesthe terminating communication terminal apparatus, and second control forforming a communication link between said first or second communicationinterface apparatus that serves the originating communication terminalapparatus and the terminating communication terminal apparatus connectedto said second communication network, in accordance with a determinationresult of said terminating apparatus determination means.
 12. Amultimedia information communication system according to claim 10 or 11,wherein said communication link formation means performs as the firstcontrol, control for sending back a response signal containing secondidentification information assigned to a communication interfaceapparatus that serves the terminating communication terminal apparatusto the communication interface apparatus as an inquiry source, andforming a communication link that connects between a communicationinterface apparatus that serves an originating communication terminalapparatus, and the communication interface apparatus that serves theterminating communication terminal apparatus, and as the second control,processing for sending back a response signal containing secondidentification information assigned to said third communicationinterface apparatus to the communication interface apparatus as aninquiry source, forming an internal communication link that connects theoriginating communication interface apparatus and said thirdcommunication interface apparatus on said first communication network,forming an external communication link between the terminating externalcommunication terminal apparatus and said third communication interfaceapparatus by requesting a call connection to said second communicationnetwork, and connecting the internal and external communication links toeach other.
 13. A multimedia information communication system accordingto claim 10 or 11, wherein said terminating apparatus determinationmeans comprises identification information storage means for prestoringfirst identification information assigned to said first and secondcommunication interface apparatuses, and first identificationinformation of each communication terminal apparatuses served by thecommunication interface apparatuses in correspondence with each other,and determines if the terminating communication terminal apparatus is acommunication terminal apparatus inside or outside said system bychecking if first identification information of a terminating apparatuscontained in the received inquiry signal is stored in saididentification information storage means.
 14. A multimedia informationcommunication system according to claim 13, wherein said terminatingapparatus determination means further comprises means for acquiringsecond identification information assigned to said first and secondcommunication interface apparatuses and the first identificationinformation of each communication terminal apparatuses served by thesecommunication interface apparatuses by inquiring of said first andsecond communication interface apparatuses.
 15. A multimedia informationcommunication system according to claim 10 or 11, wherein when areceived inquiry signal contains information indicating whether or not acall is originated to said second communication network, saidterminating apparatus determination means determines based on theinformation if the terminating communication terminal apparatus is acommunication terminal apparatus inside or outside said system.
 16. Amultimedia information communication system comprising: first and secondcommunication terminal apparatuses for exchanging information data usinga common first communication protocol or first and second communicationprotocols which are different from each other; a first communicationnetwork for transmitting information data in accordance with a thirdcommunication protocol different from the first and second communicationprotocols; first and second communication interface apparatuses forrespectively connecting said first and second communication terminalapparatuses to said first communication network; and a thirdcommunication interface apparatus for connecting said firstcommunication network to a second communication network for transmittinginformation data in accordance with a fourth communication protocoldifferent from the third communication protocol, wherein each of saidfirst and second communication interface apparatuses comprises:terminating apparatus determination means for, when a communicationterminal apparatus served by the own apparatus generates a calloriginating request addressed to another communication terminalapparatus, determining if the terminating communication terminalapparatus is a communication terminal apparatus which is served by saidfirst or second interface apparatus inside said system, or acommunication terminal apparatus which is connected to said secondcommunication network outside said system, wherein said terminatingapparatus determination means comprises inquiry means for, when acommunication terminal apparatus served by the own communicationinterface apparatus generates a call originating request addressed toanother communication terminal apparatus, multi-address transmitting aninquiry signal containing identification information corresponding tothe terminating communication terminal apparatus to all communicationinterface apparatuses connected to said first communication network; andcommunication link formation means for selectively performing firstcontrol for forming a communication link for connecting between the owncommunication interface apparatus and a communication interfaceapparatus that serves the terminating communication terminal apparatus,and second control for forming a communication link for connectingbetween the own communication interface apparatus and the terminatingcommunication terminal apparatus connected to said second communicationnetwork, in accordance with a determination result of said terminatingapparatus determination means.
 17. A multimedia informationcommunication system according to claim 1, wherein said terminatingapparatus determination means further comprises: determination means fordetermining if the terminating other communication terminal apparatus isa communication terminal apparatus inside or outside said system bymonitoring whether or not one of the communication interface apparatusesconnected to said first communication network sends back a responsesignal indicating that the apparatus serves the terminating othercommunication terminal apparatus, after the inquiry signal istransmitted.
 18. A multimedia information communication apparatusaccording to claim 17, wherein said terminating apparatus determinationmeans comprises: identification information storage means for, when theresponse signal is sent back, storing second identification information,which is contained in the response signal, and corresponds to acommunication interface apparatus that sent back the response signal,together with first identification information corresponding to theterminating communication terminal apparatus in correspondence with eachother; and determination means for, when a communication terminalapparatus served by the own communication interface apparatus generatesa call originating request addressed to another communication terminalapparatus, searching said identification information storage means forsecond identification information assigned to a communication interfaceapparatus that serves the terminating communication terminal apparatus,and determining based on the presence/absence of the secondidentification information if the terminating communication terminalapparatus is a communication terminal apparatus inside or outside saidsystem.
 19. A multimedia information communication apparatus accordingto claim 16, wherein when a call originating request sent from anoriginating communication terminal apparatus contains informationindicating whether or not a call is originated to said secondcommunication network, said terminating apparatus determination meansdetermines based on this information if the terminating communicationterminal apparatus is a communication terminal apparatus inside oroutside said system.
 20. A multimedia information communication systemcomprising: first and second communication terminal apparatuses forexchanging information data using a common first communication protocolor first and second communication protocols which are different fromeach other; a first communication network for transmitting informationdata in accordance with a third communication protocol different fromthe first and second communication protocols; first and secondcommunication interface apparatuses for respectively connecting saidfirst and second communication terminal apparatuses to said firstcommunication network; and a third communication interface apparatus forconnecting said first communication network to a second communicationnetwork for transmitting information data in accordance with a fourthcommunication protocol different from the third communication protocol,wherein said third communication interface apparatus comprises: firstidentification information acquisition means for, when an incoming callsignal reaches from an external communication terminal apparatus viasaid second communication network, acquiring first identificationinformation corresponding to a terminating communication terminalapparatus served by said first or second communication interfaceapparatus on the basis of information representing a terminatingapparatus contained in the incoming call signal; second identificationinformation acquisition means for acquiring second identificationinformation assigned to said first or second communication interfaceapparatus that serves the terminating communication terminal apparatuson the basis of the first identification information acquired by saidfirst identification information acquisition means; and communicationlink formation means for forming a communication link that connectsbetween said third communication interface apparatus and said first orsecond communication interface apparatus that serves the terminatingcommunication terminal apparatus on said first communication network onthe basis of the second identification information acquired by saidsecond identification information acquisition means.
 21. A multimediainformation communication system according to claim 20, wherein when theincoming call signal coming from the external communication terminalapparatus contains at least one of identification informationcorresponding to a terminating communication terminal apparatus and acommunication type, said first identification information acquisitionmeans determines a terminating communication terminal apparatus on thebasis of at least one of the identification information andcommunication type, and acquires first identification informationassigned to the determined communication terminal apparatus.
 22. Amultimedia information communication system according to claim 20,wherein when the incoming call signal coming from the externalcommunication terminal apparatus contains identification information ofan originating communication terminal apparatus, said firstidentification information acquisition means determines a terminatingcommunication terminal apparatus on the basis of the identificationinformation, and acquires first identification information assigned tothe determined communication terminal apparatus.
 23. A multimediacommunication system comprising:a plurality of interface apparatuses,each of which is connected to a communication terminal, and has protocolconversion means for converting a first communication protocol unique tothe communication terminal into a second communication protocoldifferent from the first communication protocol, and vice versa; anetwork for connecting said interface apparatuses to each other andtransmitting a signal in accordance with the second communicationprotocol; and a communication connection controller for controlling acommunication between the terminal devices connected to the plurality ofinterface apparatuses, wherein said communication connection controlleris provided to at least one of said interface apparatuses, and each ofsaid interface apparatuses transmits, to one communication connectioncontroller, originating side information that pertains to the interfaceapparatus which is to initiate a communication, terminating sideinformation that pertains to the interface apparatus which is tocommunicate with, and communication condition information that pertainsto communication means for performing a communication, at the beginningof the communication.
 24. A multimedia communication system according toclaim 23, wherein said communication controller acquires detailedoriginating side information, terminating side information, andcommunication condition information from a database on said network orsaid interface apparatus on the basis of the received originating sideinformation, terminating side information, and communication conditioninformation, selects an appropriate communication connection controlleron the basis of the acquired information and information that pertainsto a status of said network at the time of the communication, andtransmits information that pertains to the selected communicationconnection controller to originating and terminating side interfaceapparatuses.
 25. A multimedia communication system according to claim24, wherein each of said interface apparatuses further comprises meansfor monitoring a communication state from the originating side interfaceapparatus to the terminating side interface apparatus.
 26. A multimediacommunication system according to claim 23, wherein the originating sideinformation contains a telephone number, network number, and login name,and the communication condition information contains an audiocommunication, image communication, and data communication.
 27. Amultimedia communication system according to claim 23, wherein theterminating side information contains a telephone number, networknumber, login name, and group information required for a communication.28. A multimedia communication system according to claim 23, whereinsaid communication connection controller further comprises means forchanging a terminating side interface apparatus in correspondence with arequest from an originating or terminating side interface apparatus or achange in status of said network even after the beginning of thecommunication between the interface apparatuses.
 29. A multimediacommunication system according to claim 23, wherein when a terminatingside interface apparatus cannot answer a call, a third interfaceapparatus answers as proxy for the terminating side interface apparatus,stores communicating information, and transfers the stored informationupon call termination to the terminating side interface apparatus.
 30. Amultimedia communication system according to claim 23, furthercomprising means for converting e-mail text into audio data, and whereinaudio data of an e-mail addressed to an originating side interfaceapparatus is transmitted to the originating side interface apparatus inresponse to a request from the originating side interface apparatus. 31.A multimedia communication system according to claim 23, wherein saidnetwork transmits a signal in accordance with a protocol complying withan IEEE802 interface.
 32. A multimedia communication system according toclaim 23, wherein said network transmits a signal in accordance with aprotocol complying with an IEEE1294 interface.
 33. A multimediacommunication system comprising: a plurality of interface apparatuses,each of which is connected to a communication terminal, and has protocolconversion means for converting a first communication protocol unique tothe communication terminal into a second communication protocoldifferent from the first communication protocol, and vice versa; anetwork for connecting said interface apparatuses to each other andtransmitting a signal in accordance with the second communicationprotocol; a communication connection controller for controlling acommunication between the terminal devices connected to the plurality ofinterface apparatuses; and means for changing the communicationconnection controller in correspondence with a request from anoriginating or terminating side interface apparatus or a change instatus of said network even after the beginning of the communicationbetween the interface apparatuses, wherein said communication connectioncontroller is provided to at least one of said interface apparatuses.34. A multimedia communication system according to claim 33, furthercomprising means for changing a communication connection mode incorrespondence with a request from an originating or terminating sideinterface apparatus or a change in status of said network even after thebeginning of the communication between the interface apparatuses.
 35. Amultimedia communication system according to claim 33, wherein a thirdinterface apparatus different from originating and terminating sideinterface apparatuses sends information of the originating andterminating side interface apparatuses to one communication connectioncontroller to call the originating and terminating side interfaceapparatuses in turn and to connect the originating and terminating sideinterface apparatuses to each other so as to make the originating andterminating side interface apparatuses communicate with each other.